I don't trust my boyfriend, what should i do?

[ɱichelle]

We have beeen together for a year, but this girl has been all over him for at least 6 months; she is always posting hearts or likes in his facebook posts or instagram, she tags him on her own facebook... I told him I didn't like that and he told me she was a kid (she's in high school) and that he helped her with her family issues. But still, she tags him in things like "You're mine <3" "you belong to me <3" and i'm EXTREMELY annoyed. I was just thinking in breaking up with him, actually. When she's with him she holds his hand... I told him that had to end and he told me he wouldn't allow that kind of stuff happen again. His friends are her same friends, and I don't know what to think. She knows i'm his girlfriend, she knows we're way older but it's like she doesn't care. She even tells him to upload photos of them and he just says no. Since they're all friends, they hang out a lot, but my boyfriend and I live 2 hours away from each other, i can't go out with them always, even though they know me. We never fight, but the times we fight it's because of her. I've tried to break up with him but he's like he'll tell her to stop and she does for like 2 weeks. When we started dating he would answer or like everything that she said, but now that he knows i don't like her, he ignores everything she does on facebook. Even though he says i'm the best gf and he's only with me i can't fully trust. what to do?

[Alice]

tell the girl to STOP and back off.