Hackering off
When you bounce your junk like a sad disco ball and grind against a stupid object while you imagine you're getting laid by someone who probably has bad breath.
I hacked off in the car because I was stuck in traffic and I was bored.
I hacked off in the kitchen while my dad was cooking and he didn't even notice.
I hacked off in the hallway and the neighbor heard me and called me a weirdo.