No privacy in relationship

My bf has a close female friend he’s had for years. I don’t resent him for having friends, if the friendship was innocent I wouldn’t be worried. 3 things, they both talk in the same way. I don’t know if you understand that but they had their own way of talking but they talk like each other now. She sent him a photo of her looking up at the camera innocently with wet hair and a vest her *** took up a third of the photo, others I have shown the photo to said they think there’s nothing wrong with it. when I said it was wrong she laughed at me and said she had a boyfriend. His name is Phil and she calls him “Philly”. I feel like we should be separate, and have no question boundaries. Whenever she does something with her boyfriend she sends him photos of it and he tells her about us but I feel like it was to make her jealous? I have no privacy in my relationship, maybe I’m jealous/immature whatever the pair of them want to call me, but it feels so intrusive, she knew that we were having sex/taking pregnancy test/my nausea/our fights etc, I told him to stop and he just pulls out whatever excuse he can and keeps doing it. I could be pregnant but I don’t feel like we’re stable enough to bring a child into it but I wont live it down if I terminate .