Who's to blame for this?

ok so I’ve been hangin out with this guy who is 40 and I’m 21 first off…we went out one night and he wanted to introduce to me his friend(who is a girl) so I went and met her and we got along really well and the whole time my guy friend kept asking us to makeout or do something but we didn’t b/c it was wierd…so after 3 months of hangin out with my guy friend we went out and got some drinks and ended up hooking up and it wasnt akward b/c when we hang out we cuddle all night and stuff like that so it was just about time it finally happened…last week he went away on vacation and the girl called me up and asked me if I had been sleeping with him and I said yes and she said well me too like I wasn’t mad or nething b/c we rnt’ dating me and my friend we’re just friends but this girl like just kept talkin bout it so I ended up getting upset b/c I thought I had a chance to date him…but since he was gone I’ve been hangin out with this girl and all she keeps sayin is your over with him rn’t u , your not going to do nething with him nemore are you and I say no but I also found out that she has had a boyfriend the whole time so I don’t know what to say to either of them when we all sit down and talk together as a group…but my question is is she the one who is jealous of his and my friendship or is he really the one to blame for all this?