He's my best friend's crush

okay so my best friend always tells me about this boy that inbox's her and calls her, she is obsessed with him and i also have him as a friend on facebook. he liked a couple of my 'like for..' statuses and i always do them.i did a like for a tbh one day and he replied constantly flirting.i didnt want to show my friend because she would hate me... she cracked it at me cause he liked my status.he promised me that he wouldnt tell my friend that we talk and yestreday he asked to meet up and just "kick back" so i did. my friends in bali at the moment. when i saw him he was nice and we just talked and walked but then he started to playfully push me, hug me , kiss my head or hold my hand just flirt a lot , i didnt say anything.we were on a bridge and he asked to go to the park under and i said okay. when we go there he sat down i stayed standing and he randomly kept complementing me, he grabbed me and started to feel me up and kissed my neck and face.. from then i knew what he was trying to do i suddenly remembered who he was and i sort of pushed away and was like no no no its not right stuff like that but he didnt really listen and he continued.he wouldnt give up and he kept trying to reassure me. i feel terrible about what happened!? shes my bestfriend she doesnt know though...he might meet up with her when she comes back im worried what should i do??

So firstly you need to think who's company is more important to you - this boy or your best friend? Secondly, you need to try and have a reasonable conversation about this with your friend. It's better that she finds out about this meeting from you than someone else. This means that it is harder for her to accuse you of going behind her back. However it is unlikely that she'll take this news kindly however you put it. Make it clear that when you met up with him you didn't intend for stuff to happen. Finally, this boys sounds like an asshole if he would try to get off with a girl and then go for her best friend when she returns from holiday. Anyway, mates before dates and that :) I hope you stay friends with your best friend it would be sad if you fell out over an asshole :( I'm sorry if this wasn't much help