When a male ejaculates into his hand. He then proceeds to rub the semen onto the testicle hair and then runs the testicle hair over the woman's face. Hence, giving her the dirty paintbrush
I can't go out tonight... My wife wants to try the dirty paintbrush and I can't turn it down!
by Mexidong June 25, 2018
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When a man has anal sex with a woman, then uses the remaining excrement on his dick to paint on the woman's back.
Clarke: I brought Suz over last week and we got a little frisky.

JP: What'd you guys do?
Clarke: Well, I fucked her in the ass, then used the leftover shit on my dick to paint on her back. We called it the dirty paintbrush.
JP: That's fucking disgusting
by wendypowell October 21, 2018
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