I think my friend's boyfriend is interested in me. He is quite nice to me and gets defensive of me when my friend jokingly insults me. He even said to her he was going to text me happy birthday which she wondered how he got my number. My friend text him off my phone the once but I showed her the deleted sent items box straight away after she sent it as I didn't want her think I had his number but he kept mine.
He speaks to her like dirt and gets angry easily with her. When I had a guy problem the other week he whispered to me that he wasn't worth it and held my arm. I have caught him look at me before too. I really don't feel comfortable as he is not my type and I certainly don't mess around with friend's boyfriends. How should I act?