user21800: I am trying to find sources of info of if the Buddha ever explained any reason why we as humans are afflicted by sexual desire.
Conventionally we are animals so are innately afflicted with a predisposition towards reproduction, with sexual desire itself being enticed by physical pleasure.
Just want to know if the Buddha explained this desire in any depth.
Obviously this issue would have come up within the sangha.

user254: Most of his talks were to monks, and so -- by definition, of "monk" -- not sexual intercourse.
Instead of "being enticed by physical pleasure", I think he more often explained it as an attraction to "form", including "sight-objects".
I think it's a question of, "To what does the heart leap up?"
So some people might leap up at the sight of some body.
It's also a question of "effluents" -- having seen, there are consequences like internal dialog, like I don't know, "Oh look! Will she...? What if I...? But..."
Conversely I think that someone who is "released" is "released from effluents through lack of clinging".
And that release comes through practice.

Nava Sutta
In the same way, even though this wish may occur to a monk who dwells without devoting himself to development — 'O that my mind might be released from effluents through lack of clinging!' — still his mind is not released from the effluents through lack of clinging. Why is that? From lack of developing, it should be said. Lack of developing what? The four frames of reference, the four right exertions, the four bases of power, the five faculties, the five strengths, the seven factors for Awakening, the noble eightfold path.


user471: Here's a sutta quote on the sexual identities and sexualities of men and women, and how it affects their mind:

A woman focuses on her own femininity: her feminine moves, feminine
appearance, feminine ways, feminine desires, feminine voice, and
feminine adornment. She’s stimulated by this and takes pleasure in it.
So she focuses on the masculinity of others: masculine moves,
masculine appearance, masculine ways, masculine desires, masculine
voice, and masculine adornment. She’s stimulated by this and takes
pleasure in it. So she desires to bond with another. And she desires
the pleasure and happiness that comes from such a bond. Sentient
beings who are attached to their femininity are bound to men. This is
how a woman does not transcend her femininity.
A man focuses on his own masculinity: his masculine moves, masculine
appearance, masculine ways, masculine desires, masculine voice, and
masculine adornment. He’s stimulated by this and takes pleasure in it.
So he focuses on the femininity of others: feminine moves, feminine
appearance, feminine ways, feminine desires, feminine voice, and
feminine adornment. He’s stimulated by this and takes pleasure in it.
So he desires to bond with another. And he desires the pleasure and
happiness that comes from such a bond. Sentient beings who are
attached to their masculinity are bound to women. This is how a man
does not transcend his masculinity. This is how one is bound.
AN 7.51

The seven sexual fetters, beyond the act itself, are explained in this sutta quote below:

“But what, Master Gotama, is a break, taint, stain, or mar in
celibacy?”
“Firstly, an ascetic or brahmin who claims to be perfectly celibate
does not mutually engage in sex with a female. However, they consent
to being anointed, massaged, bathed, and rubbed by a female. They
enjoy it and like it and find it satisfying. This is a break, taint,
stain, or mar in celibacy. This is called one who lives the celibate
life impurely, tied to the fetter of sex. They’re not freed from
rebirth, old age, death, sorrow, lamentation, pain, sadness, and
distress. They’re not freed from suffering, I say.
Furthermore, an ascetic or brahmin who claims to be perfectly celibate
does not mutually engage in sex with a female. Nor do they consent to
massage and bathing. However, they giggle and play and have fun with
females. …
they gaze into a female’s eyes. …
they listen through a wall or rampart to the sound of females laughing
or chatting or singing or crying. …
they recall when they used to laugh, chat, and have fun with females …
they see a householder or their child amusing themselves, supplied and
provided with the five kinds of sensual stimulation. …
They don’t see a householder or their child amusing themselves,
supplied and provided with the five kinds of sensual stimulation.
However, they live the celibate life wishing to be reborn in one of
the orders of gods. They think: ‘By this precept or observance or
mortification or spiritual life, may I become one of the gods!’ They
enjoy it and like it and find it satisfying. This is a break, taint,
stain, or mar in celibacy. This is called one who lives the celibate
life impurely, tied to the fetter of sex. They’re not free from
rebirth, old age, death, sorrow, lamentation, pain, sadness, and
distress. They’re not free from suffering, I say.
As long as I saw that these seven sexual fetters—or even one of
them—had not been given up in me, I didn’t announce my supreme perfect
awakening in this world with its gods, Māras, and Brahmās, this
population with its ascetics and brahmins, its gods and humans.
AN 7.50

MN 75 talks about burning with sensual fever, and the more one indulges in sensual pleasures, the more the sensual craving increases. This applies to all sensual pleasures, not just sex.

"Now suppose that there was a leper covered with sores & infections,
devoured by worms, picking the scabs off the openings of his wounds
with his nails, cauterizing his body over a pit of glowing embers. The
more he cauterized his body over the pit of glowing embers, the more
disgusting, foul-smelling, & putrid the openings of his wounds would
become, and yet he would feel a modicum of enjoyment & satisfaction
because of the itchiness of his wounds. In the same way, beings not
free from passion for sensual pleasures — devoured by sensual craving,
burning with sensual fever — indulge in sensual pleasures. The more
they indulge in sensual pleasures, the more their sensual craving
increases and the more they burn with sensual fever, and yet they feel
a modicum of enjoyment & satisfaction dependent on the five strings of
sensuality.
MN 75


21800: <p>I am trying to find sources of info of if the Buddha ever explained any reason why we as humans are afflicted by sexual desire.
Conventionally we are animals so are innately afflicted with a predisposition towards reproduction, with sexual desire itself being enticed by physical pleasure.
Just want to know if the Buddha explained this desire in any depth.</p>
<p>Obviously this issue would have come up within the sangha.</p>
 254: <p>Most of his talks were to monks, and so -- by definition, of &quot;monk&quot; -- not sexual intercourse.</p>
<p>Instead of &quot;being enticed by physical pleasure&quot;, I think he more often explained it as an attraction to &quot;form&quot;, including &quot;sight-objects&quot;.</p>
<p>I think it's a question of, &quot;To what does the heart <a href="https://www.accesstoinsight.org/search_results.html?q=leap+up" rel="nofollow noreferrer">leap up</a>?&quot;</p>
<p>So some people might leap up at the sight of some body.</p>
<p>It's also a question of &quot;effluents&quot; -- having seen, there are consequences like internal dialog, like I don't know, &quot;Oh look! Will she...? What if I...? But...&quot;</p>
<p>Conversely I think that someone who is &quot;released&quot; is &quot;released from effluents through lack of clinging&quot;.</p>
<p>And that release comes through practice.</p>
<blockquote>
<p><a href="https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.101.than.html" rel="nofollow noreferrer">Nava Sutta</a></p>
<p>In the same way, even though this wish may occur to a monk who dwells without devoting himself to development — 'O that my mind might be released from effluents through lack of clinging!' — still his mind is not released from the effluents through lack of clinging. Why is that? From lack of developing, it should be said. Lack of developing what? The four frames of reference, the four right exertions, the four bases of power, the five faculties, the five strengths, the seven factors for Awakening, the noble eightfold path.</p>
</blockquote>
 471: <p>Here's a sutta quote on the sexual identities and sexualities of men and women, and how it affects their mind:</p>
<blockquote>
<p>A woman focuses on her own femininity: her feminine moves, feminine
appearance, feminine ways, feminine desires, feminine voice, and
feminine adornment. She’s stimulated by this and takes pleasure in it.
So she focuses on the masculinity of others: masculine moves,
masculine appearance, masculine ways, masculine desires, masculine
voice, and masculine adornment. She’s stimulated by this and takes
pleasure in it. So she desires to bond with another. And she desires
the pleasure and happiness that comes from such a bond. Sentient
beings who are attached to their femininity are bound to men. This is
how a woman does not transcend her femininity.</p>
<p>A man focuses on his own masculinity: his masculine moves, masculine
appearance, masculine ways, masculine desires, masculine voice, and
masculine adornment. He’s stimulated by this and takes pleasure in it.
So he focuses on the femininity of others: feminine moves, feminine
appearance, feminine ways, feminine desires, feminine voice, and
feminine adornment. He’s stimulated by this and takes pleasure in it.
So he desires to bond with another. And he desires the pleasure and
happiness that comes from such a bond. Sentient beings who are
attached to their masculinity are bound to women. This is how a man
does not transcend his masculinity. This is how one is bound.<br />
<a href="https://suttacentral.net/an7.51/en/sujato?layout=plain&amp;reference=none&amp;notes=asterisk&amp;highlight=false&amp;script=latin" rel="nofollow noreferrer">AN 7.51</a></p>
</blockquote>
<p>The seven sexual fetters, beyond the act itself, are explained in this sutta quote below:</p>
<blockquote>
<p>“But what, Master Gotama, is a break, taint, stain, or mar in
celibacy?”</p>
<p>“Firstly, an ascetic or brahmin who claims to be perfectly celibate
does not mutually engage in sex with a female. However, they consent
to being anointed, massaged, bathed, and rubbed by a female. They
enjoy it and like it and find it satisfying. This is a break, taint,
stain, or mar in celibacy. This is called one who lives the celibate
life impurely, tied to the fetter of sex. They’re not freed from
rebirth, old age, death, sorrow, lamentation, pain, sadness, and
distress. They’re not freed from suffering, I say.</p>
<p>Furthermore, an ascetic or brahmin who claims to be perfectly celibate
does not mutually engage in sex with a female. Nor do they consent to
massage and bathing. However, they giggle and play and have fun with
females. …</p>
<p>they gaze into a female’s eyes. …</p>
<p>they listen through a wall or rampart to the sound of females laughing
or chatting or singing or crying. …</p>
<p>they recall when they used to laugh, chat, and have fun with females …</p>
<p>they see a householder or their child amusing themselves, supplied and
provided with the five kinds of sensual stimulation. …</p>
<p>They don’t see a householder or their child amusing themselves,
supplied and provided with the five kinds of sensual stimulation.
However, they live the celibate life wishing to be reborn in one of
the orders of gods. They think: ‘By this precept or observance or
mortification or spiritual life, may I become one of the gods!’ They
enjoy it and like it and find it satisfying. This is a break, taint,
stain, or mar in celibacy. This is called one who lives the celibate
life impurely, tied to the fetter of sex. They’re not free from
rebirth, old age, death, sorrow, lamentation, pain, sadness, and
distress. They’re not free from suffering, I say.</p>
<p>As long as I saw that these seven sexual fetters—or even one of
them—had not been given up in me, I didn’t announce my supreme perfect
awakening in this world with its gods, Māras, and Brahmās, this
population with its ascetics and brahmins, its gods and humans.<br />
<a href="https://suttacentral.net/an7.50/en/sujato?layout=plain&amp;reference=none&amp;notes=asterisk&amp;highlight=false&amp;script=latin" rel="nofollow noreferrer">AN 7.50</a></p>
</blockquote>
<p><a href="https://www.accesstoinsight.org/tipitaka/mn/mn.075x.than.html" rel="nofollow noreferrer">MN 75</a> talks about burning with sensual fever, and the more one indulges in sensual pleasures, the more the sensual craving increases. This applies to all sensual pleasures, not just sex.</p>
<blockquote>
<p>&quot;Now suppose that there was a leper covered with sores &amp; infections,
devoured by worms, picking the scabs off the openings of his wounds
with his nails, cauterizing his body over a pit of glowing embers. The
more he cauterized his body over the pit of glowing embers, the more
disgusting, foul-smelling, &amp; putrid the openings of his wounds would
become, and yet he would feel a modicum of enjoyment &amp; satisfaction
because of the itchiness of his wounds. In the same way, beings not
free from passion for sensual pleasures — devoured by sensual craving,
burning with sensual fever — indulge in sensual pleasures. The more
they indulge in sensual pleasures, the more their sensual craving
increases and the more they burn with sensual fever, and yet they feel
a modicum of enjoyment &amp; satisfaction dependent on the five strings of
sensuality.<br />
<a href="https://www.accesstoinsight.org/tipitaka/mn/mn.075x.than.html" rel="nofollow noreferrer">MN 75</a></p>
</blockquote>
