Best friend, I miss him so much

I saw my best friend yesterday for the last time for two and a half weeks as he is going on holiday to see his dad, step mum and half sister. And I already miss him so much. About 5-10mins ago I was just playing my ds and listening to (bonjovi - living on a prayer) and I dont know why but my friend came into my head for like a second and I realised I really missed him and burst out crying for him.

Why do I miss him so much?
why did I think of him then cry?
And now if I think about something else and he comes back into my head I feel like crying?

Any help?? xxx

you love him!!! lol. That's so sweet

but I have a boyfriend who I love