References old Cheech&Chong comedy bit. A rottenpeter is a guy who will not only let any female use his body for sex, but is also just dumb enough not to use any kind of protection and acquires an STD as a result.

In conversation:

Q:"Hey girl, you ever thought about getting that guy in bed?"

A:"No way. He's so easy he's a rottenpeter."
by Annonie November 28, 2007
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