Urgent. id like girl comment but boys can give good advice too(friends with benifits question)?

Alright so I am a highschool sophmore I'm kinda one of the prep ish party animals one story that is commanly told is when i bought a pint of patron and drank it and banged my ex girlfriends bff. Anyway that is just backround info to kind of set me on the socail ladder to you. So not wonderful with the ladies but i get round. currently im engaged in a friends with benifits situation with a pretty freshman girl we make out ive slipped her a finger and such. its my highschool common knowledge that we are some kind of 'thing' so everything is great but im not a faithful drunk but she doesnt know im chasin tail while she is thinking we are like together is this bogus. Also more information is she hates being in a relationship, but im pretty sure she thinks we are together so we are unofficailly dating. I really do like this girl she is funny, pretty, and seriosly any hot girl who wants to be fwbs is legit i dont like 'cheating' on her but if you have ever consumed 4 double shots on a dare then you know what that does to your minds process. anyway this is my delema. also this isnt english class so i did spell check or peer edit so lets not tip on my dick for my lack of care