Why she keep trying to make me jealous?

this girl i hang with sometimes. she always talking about how guys give her roses and she hangs out with them and all. she says she just wanna be friends, but always looking at my tex.t mes.sages and asking me if i cheat, then something i said slipped and i said i slept with a girl over the weekend and she was kinda upset and totally jipped me out of 2 bucks, which she has never done before.