Should I end Things with him?

OK I like this guy and he likes me too or so he says. He has a girlfriend but still says that were gonna kiss and all that stuff when we hang out on saturday. He was talking to my friend and asked her if he will kiss him. I found out because she told me. He flirts with evryone. Should I just end things? What are you opinions? oy yeah I have to see him saturday because his uncle is my stepdads best friend.