How do you get sex for free?

Getting married and having a wife is (obviously) NOT free.
Having a girlfriend who always bugs you for rides, dinners, movies, etc. is NOT free.
Paying to buy a girl a drink in a bar so she'll sleep with you that night is NOT free.
Paying for a girl at a brothel is (obviously) NOT free
Raping a girl, getting caught, and facing the legal consequences is NOT free.

So is it even possible to get free sex (as a guy)?