What would you do?

I like this girl, but she has a girlfriend. She says she loves her, but her girlfriend and her don't really get along. Her girlfriend always is putting her down, but she told me she likes me and when she is with me, she is so happy and last night she went out to eat with me and then on our way back she held my hand and then kissed me when I got home and then we made out and she says she really likes me and I really like her. What should I do?