How do i get someone thats in a relationship to give me a chance?

ok there!s this chick ive been hanging with for a while now and shes in a relationship but theres been a certain funny feel when i get a round her weve went out a lot together with a group of friends but neva alone and recently we were out with friends and had some drinks and dance then we went to tha club after tha club we had a party in a hotel room and we chill and went to sleep and we started messing around and the next day i hit her up and apolozied but she said there was no need to cuz shes been likeing me for a while and that something she been wanting to do its been werid hanging with her since i dont wanna be a home wrecker but her friends say she having doubts about her guy but shes loves him or thats what she say wht should i do