Guy 1- The day I can't get a boner is the day I die.
Guy 2- What?! What about your family?
Guy 1- I want to die having a drug fuelled sex heart attack.
A sex drug is someone that is so hot, that when you are having sex (or makeout), you keep wanna come back and restart. It's like an addiction.
Jason and Travis are having a discussion of how their girlfriends are the hottest in high school.
Jason : I think I'll be going now.
Travis : Don't catch too much of your sex drug!
Jason : High school sex isn't really my thing.
Travis : Syke!