crush help

so there’s this guy. he’s my best friends little brother. but we are almost the same age( my best friend is older) anyway. we’ve always been friends and all because i’m friends with his brother so we’ve always spent time together. we always flirt and stuff and one night we got drunk and had sex. after that it became a normal thing so we were friends with benefits. we had talked about how we wanted to keep it no strings attached and at the time i agreed. well i ended going to meet his dad with my best friend and that trip changed everything. he became more openly touchy with me around other people and it seemed like he started to like me. he even slipped up and called me babe twice. and not even during sex. but a couple months go by and i’m trying to hang out and i invite him to spend the night and stuff but he always has a reason why he can’t. then he came to this party with me so i thought he was over it. but now we don’t even really talk anymore besides like one snapchat a day to keep our streak. but it was so sudden. he went from acting like he potentially wanted to date to not even wanting to hang out and i don’t know what to do. it’s just so weird to me. any advice?