Used to describe various states of erection. SEP is an acronym for Semi-Erect Penis which indicates a slightly heightened state of arousal, NEP stands for Non-Erect Penis which is completely and utterly flacid and FEP which is Fully-Erect Penis which indicates a maximum state of arousal and erection.
Tom "What do you think of that chick, are you getting a SEP, NEP, FEP?"

Vince "She's giving me a FEP, thats what I think"
by vinnyg December 4, 2007
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