Originating in Central KY, 'sfepp' is slang word for casually fondling, feeling up, playing around with, squeezing (lightly) a friend or aqquaintance's genitals or breasts. It is most commonly used among horny teenagers and groups of younger adults to describe the non-sexual yet still arousing general flirty-touching among friends of opposite and same sexes.
Emily- I walked up behind Jas in the hallway and sfepped him while he was putting his books in his locker, you should have seen the look on his face!
Molly- We should play *sfepp* coin, heads, i sfepp you, tails, you sfepp me (played on long school schoolbus rides)
Joe- We were bored and tired on the way back from Texas, so Jesse and I sfepped each other... no big deal, just casual goofing around and teasing ;)
casual, teasing touching of a friend's (not someone a person is in a relationship with) genitals or breasts
scene- girls and guys standing outside of mall- lots of flirting, joking around, girl walks up to one of the guys, grabs at package, guy yells " **** just sfepped me!" laughter ensues.