beating penis

Rough, borderline abusive male masturbation (self or otherwise).

-Misheard from Starbomb's song "Rap Battle: Ryu vs. Ken"

-Think you can stop beating penis long enough for this rap battle to the death?

-Probably!

-Why are you in the hopsital?
-I was beating penis a bit too enthusiastically, I'm checking to make sure I didn't get an infection.

beating a dead penis

When someone excessively pesters you about whether you had an erection in response to seeing someone

Peter: So you had a massive boner the entire time, right?
Paul: No, dude, you're beating a dead penis.

beat down by penis

Getting your ass handed to you by a erect or flacide penis

Sally got beat down by penis.