how would you feel

hi!

basically, my boyfriend has a female friend he’s worked with for a while, longer than we’ve been together. i never really heard about her (maybe once a month on average) until the past week, all of a sudden they seem very close, always messaging, he’s always talking about her, he went to rescue her when her car broke down the other day etc.

i’m totally fine with the friendship, after all she was there before i was around, but just not as close. however i’m obviously slightly worried now due to how close they’ve gotten all of a sudden, but i’ve just found out she had a partner but they recently split up, and she started trying to get with another colleague of theirs, who is in a relationship.

i dont know if im totally overreacting about being concerned about how close their getting given this information, and theyre also planning to meet soon, alone. my partner asked if i was okay with this, i admitted i wasnt very comfortable, due to the factors stated. and he’s been completely rude about it. called me insecure etc. i was completely respectful and said he can obviously do as he pleases, i’m not here to give permission, but told him how i felt as he asked.

but it has made me worry that i’m insecure and totally overthinking and reacting, and was wondering how anyone else would feel in this situation.

any help is appreciated!!