sexpathy
Is the moment when you think of having sex with your partner for you are obliged to, and is always associated with the thought of breaking up with him/her soon.

In other words, feeling guilty or sorry for your partner for soon you will be breaking up with them, thus you feel like you have to have sex with them to feel less guilty.

In short "goodbye sex" or "last sex"

Derived from sex + sympathy
Dude 1:I can't feel her emotion anymore, last time we're together it just felt like she's just giving me sexpathy.
Dude 2: it's okay bro
Dude1: Yeah! doesn't matter, had sex.

--

Girl 1:After what happened you still seeing him.
Girl 2:Nothing special actually I just feel like sexpathy that's all.