1) The dude with whom you share a poon in a MMF threesome.
2) A female roomie that while not involved with you, still helps you out with more than the dishes & laundry.
1) I was totally poomies with (insert name) last night after that party and now I can't look him in the eye.
2) My cute poomie took pity on my blue balls
last night and sucked me off after dinner.