Ok I know this is kinda fucked up. But I was thinking - if aliens watched us, sorta like could look in our houses and study us like lab rats, what would they think of us jerking off? I mean if you really think aobut it its a pretty fucked up thing to do.
The male of the species is agressively rubbing a small tube located in the middle of his torso. He looks angry. He continues agressive motion until tube throws up.
They probably wonder why we don't do this to our arm or foot or something. I think if aliens abducted me and used my brain to understand humans they'd leave so fucking confused that they'd never come back. Hey I could single handedly prevent an interstallar war and enable our species to exist forever. You're welcome!