need advice

i need advice. there's this boy and we've been talking for a few months now, we've had sex a few times already. but lately, he's been acting different and short with me. i feel like he's talking to someone else.  i don't know what to do, im a 'crybaby' i guess you could say. he's all ive been thinking about. apparently lastnight, i heard that he was going out with his friends that are boys, and they were going to a girls house.