Dude, I was so unhappy about my girl, until I spoke to my serotonin donor who really helped me feel better

Tim: Zack, is that your exgirlfriend?
Zack: No, she's an expotential. We never actually dated...

The piece of shit thought the serotonin donor was there to say something funny instead of to let him/her know that he/she needed to tone his/her bullshit down.

I'm not feeling too good today. I'm gonna go watch Chan's Room cause he's my serotonin donor