Do i still have feelings for him?

Your friend isn't a very good one. It's not right for your friend to go out with your ex, I mean, id feel a little uncomfortable about that, wouldnt you? And when she said "no hes dating me." well thats self-fish. She went out with your ex, why can't you just have his number? Thats just not right. Talk to your friend and tell her to think about other people before herself.