user5315: There is a true story where a couple just got married. Soon after marriage, the wife is diagnosed with certain illness by the doctor. To make it short, because of the illness, the wife is not allowed to have sexual intercourse. The wife, however, tells the husband if needed he can have sexual intercourse with other woman to meet his biological need. 
In this particular case, if the husband has sexual intercourse with other woman, does he break the 3rd precept? Any source provided to back up the answer would be great.

user760: This is the third precept in Pāḷi:

kāmesu micchācārā veramaṇī-sikkhāpadaṃ samādiyāmi


kāmesu is a locative (“in”) form of the word kāma and means “sexual desire”
micchācārā consists of micchā, which means “wrong”, and ācārā, which is an ablative (“from”) form of ācāra and means “way of behaving”
veramaṇī-sikkhāpadaṃ samādiyāmi means “I undertake the precept of abstaining”

All the precept says is that one has to abstain from behaving badly in the matter of sexual lust. This is a pretty vague statement that depends on one's culture, and Buddhists from different cultures would surely disagree about what it exactly means.
That said, even a traditional Buddhist society could accept polyandry, so we can expect that most Buddhists would also accept the situation you describe, which can be classified as a form of polygamy.

user111: It does not break the third precept if the husband has the wife's willful(not forced) consent. It's somewhat similar to kings having more than one queen. 
Having said that, there is no such thing as a "biological need" regarding sexual pleasures. Water is a biological need, air is a biological need, food is a biological need as you cannot survive without them. You do not need sex to live.

5315: <p>There is a true story where a couple just got married. Soon after marriage, the wife is diagnosed with certain illness by the doctor. To make it short, because of the illness, the wife is not allowed to have sexual intercourse. The wife, however, tells the husband if needed he can have sexual intercourse with other woman to meet his biological need. </p>

<p>In this particular case, if the husband has sexual intercourse with other woman, does he break the 3rd precept? Any source provided to back up the answer would be great.</p>
 760: <p>This is the third precept in Pāḷi:</p>

<blockquote>
  <p>kāmesu micchācārā veramaṇī-sikkhāpadaṃ samādiyāmi</p>
</blockquote>

<ul>
<li><em>kāmesu</em> is a locative (“in”) form of the word <em>kāma</em> and means “sexual desire”</li>
<li><em>micchācārā</em> consists of <em>micchā</em>, which means “wrong”, and <em>ācārā</em>, which is an ablative (“from”) form of <em>ācāra</em> and means “way of behaving”</li>
<li><em>veramaṇī-sikkhāpadaṃ samādiyāmi</em> means “I undertake the precept of abstaining”</li>
</ul>

<p>All the precept says is that one has to abstain from behaving badly in the matter of sexual lust. This is a pretty vague statement that depends on one's culture, and Buddhists from different cultures would surely disagree about what it exactly means.</p>

<p>That said, <a href="https://en.wikipedia.org/wiki/Polyandry_in_Tibet" rel="nofollow noreferrer">even a traditional Buddhist society could accept polyandry</a>, so we can expect that most Buddhists would also accept the situation you describe, which can be classified as a form of polygamy.</p>
 111: <p>It does not break the third precept if the husband has the wife's willful(not forced) consent. It's somewhat similar to kings having more than one queen. </p>

<p>Having said that, there is no such thing as a "biological need" regarding sexual pleasures. Water is a biological need, air is a biological need, food is a biological need as you cannot survive without them. You do not need sex to live.</p>
