Best friend or Boyfriend! Please help?

There's this guy, who's my best friend and we've been friends for over a year now:). We're sorta like FWB (Friend's With Benefits) tho:P. Not as serious as making out, but we're 'cuddle buddies' and hug every 2 minutes:P. Lately, its been getting more serious and his friend's tell me he likes me... Which I really don't have a problem with... Coz I sorta like him too, I just don't wanna ruin our friendship... AND I have a boyfriend :|. He's been really mean lately, and telling me my friends are annoying and he hates them, which I really don't appriciate... And everytime my bbm status is about my best friend, he gets all agro and jealous... Its really starting to annoy me and I don't know what to do!?:( best friend or boyfriend??