A neologism between the words tripping and creeping. So pretty much a person who secretly knows information about you by creeping on you, and is tripping because they think you don't know.
"Dude that girl who's ex is dating my ex, wants me to go the club with her.", "Oh she treepin' on you then!
In tennis the term "treeing" refers to the act of hitting every ball as hard as you can, going for winners at inappropriate times, and/or playing in such a way that depicts oneself to be playing without an essence of strategy.
Joe won the match against the one seed, but he was treeing out of his mind.
Treeing originated in Vero Beach, FL in the 1980s and it means to play incredible tennis, without really missing, for an extended period as to win an epic upset match, or just to have an amazing tennis day. It transcends just playing well- movement, concentration, even romance- everything just clicks. It's a very rare occurrence and one can only hope it's during an important match so there can be many witnesses.
Miles beat the top seed from Miami in front of all his friends and family, his ex-gf and new gf, after treeing his ass off in the third set 6-1.