My boyfriends best friend ..... ?

So i've been dating my boyfriend for 11months ,( we're all 17) i'm really crazy about him & hes just amazing .I told him a few nights ago I was falling in love with him & he just quickly changed the subject.I don't understand why but it just wasn't what I wanted to hear. Now ,my boyfriends best friend is also Phenomenal. We have been the best of friends for about 3 & hes clearly been trying to make more of that. Like , posting " boyfriend like " stuff on my facebook wall , sending me I love you soo soo much text's in the middle of the night . ( ect ) Stuff like that . This guy is an extreme player & is a recent Ex of my closest BESTEST friends .I've been friends with him for the longest but I really don't know if I can believe him , I think I can because of how close friends we are . I want to believe what hes saying is from the heart , but I still have my boyfriend who isn't saying anything at all . What should I do ? ):