Is it okay for a girlbestfriend of his to always set him as profile picture, cover photo, and even both lock and home screen?

Dvies
So I had this really great relationship with my boyfriend, not until he met a girl bestfriend that I haven't been knowing recently, During those days I had a bad feeling because he hasn't been replying too many days with me on Facebook either calls, messages. Until I made a fake account to spy on him, and he had been posting pictures of him and his so called bestfriend. I've always been curious about his girl bestfriend's profile she has been setting him as her cover photo, next she put her profile picture where they were together in 1 photo, she has been posting moments with him like they're a couple. I even read some of his girl bestfriend's friends' comments there they were shipping both of them there were comments like "Maybe he already replaced you." she replied,"No he won't." I really felt jealous, I even tried contacting her to talk to her about this I'm not feeling any comfortable. when I tried reaching her out she instantly blocked me after reading my message. She knew that I was his girlfriend, I found out he was living with her in the same house with the girl's family together. his entire excuse whenever I asked him that was, Because he wanted to get closer to me whenever he needs to travel because his home is too far away from mine. I didn't believed this enough. I asked him if I can check the girl's phone, so when I pressed the button, I felt even more jealous, because he was the one who was set as HER homescreen wallpaper and lock screen wallpaper. I even saw many of their pictures together on the Gallery. Next, I was curious enough about their conversation on facebook together, I caught them together calling eachother BABE and BABY. I bursted out in anger but still he makes me believed his reason as because they were "closed friends" "bestfriends". even I have some guy friends but I would never do what the girl just did. especially when she knows he has a girlfriend.
Is it okay for a girlbestfriend of his to always set him as profile picture, cover photo, and even both lock and home screen?
7 Opinion