u/Far_Try_5056

My boyfriend and I have been dating for almost 5 years, and from the beginning of our relationship we have had a mutual friend, Sarah. Sarah has become obsessively attracted to my boyfriend and pushed away all other friends as her obsession took hold. She will follow him around everywhere he goes at any event they're both at, even if I'm there, and makes no effort to hide her attraction.

Recently she seems to have decided that she wants to be the one dating my boyfriend, at any cost necessary. It started with her sending my boyfriend a text where she said that she didn't care how I felt about her and that I could "find someone else" and that she can't. After sending the text to my boyfriend, she sent me a screenshot of the text where I also found out that my boyfriend is saved in her phone as "Beloved". Since then she has been sending me screenshots of anything that could imply that my boyfriend isn't happy in our relationship, which I have been immediately sending to my boyfriend.

I and Sarah's older sister, who is a friend of mine, are concerned about how far Sarah is willing to go to get what she wants. She has been manipulative of my boyfriend, who is trying to simply be a good friend, and avoidant when conversation about the situation is brought up by her sister. Sarah doesn't seem to have any respect for me or my relationship with my boyfriend and has heavily implied that she wouldn't respect any requests from me regarding her behavior. Family and friends that have been around while Sarah has been following my boyfriend everywhere have expressed disapproval of the behavior but have only made comments about the behavior to me while my boyfriend and Sarah are elsewhere.

I have complete trust that my boyfriend doesn't reciprocate any romantic feelings for Sarah, however both I and Sarah's sister are concerned that both my boyfriend's and Sarah's mental health will suffer if this situation continues without change.

WIBTAH? Any advice is appreciated.