Me and my Friend like the same guy .. but He likes me ! What should i do ? please help! thank you (:?

Last year I dated this guy for quite a while. Well one day Mel my friend decided to look him up on Facebook then get his number out of my phone. She has been obsessed with him ever since. She has been begging me to invite her over to my house, so i finally did. But, I found out later she only wanted to, so she could hang out with my ex(hes my neighbor). Well, I still like him, never stopped. We make out and hang out almost every night but we're not dating yet . She thinks that he likes her, when he in real life is scared of her. She wont stop bugging me about him to where she will message me 5 to 6 times a day asking about him. Mel doesn't know anything that has been going on with him and I. She thinks that we are just friends and that i'm trying to set them up together. Jacob and i want to date but we cant until i get things right with her. I don't want to lose her as a friend but I think i'm in love with this guy. What should i do ?