my friend once came over and just jacked off in front of me
You should've joined in.
Unless he was jacking off TO you.
Then just kick him in his erect pee-pee.
My friend brings over a 3DS and plays Super Smash Bros the whole time when minecraft LAN doesn't work, and when he's the first zombie in Gmod zombie survival servers.
Something that I do at my friends house: When I'm getting a bit bored of the games we're playing together, I'll tell him that I need a stretching break.
I then proceed to chase after and play with his cats.