Singles And Dating Open Question My Boyfriend Still Talks To His Ex What Do I Do

Before we dated he used to talk about her all the time and why he hates her. He hated her because apparently she cheated on him and he was really mad. But now she's dating his best friend so they've been around eachother a lot. One day my boyfriend talked to her about what happened the day she cheated on him and it turns out she didn't do it, some guy just kissed her cause he didn't know she was dating at the time so now that my boyfriend knows that, he doesn't hate her anymore and talks to her. He tries to get me to be friends with her and one day me my boyfriend his ex and his bestfriend hung out and I was really uncomfortable. His ex and her bf made out in front of us the whole time, I feel like its a way of saying "look at what youre missing out on" to my boyfriend and she never talked to me. my boyfriend slept over at his best friends house with his gf there so them three had a sleepover. That bothered me. What do I do? I don't want to seem 2 possessive and not let him talk 2her

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