AITAH For being jealous of my bf’s relationship with his cousin sister…

Me (22F) and my bf (23M) have been in a relationship for 2years. He has an older brother who is 30 and lives away. My bf has a cousin (F) who is a year older than him and she has a sibling (m). This cousin is pursuing her studies and also lives away. She comes once every 2-3 months for a month and goes back to uni/work.

My bf has been really close to her and her brother when they were children. I have heard about their stories growing up and all. When me and my bf got together, he told me he had an instagram which he opened after he met me to check my profile and told me himself that he will only follow me and no one else. Well time passed and I was the only one he followed until one fine morning where he decided to follow her cousin too. It seemed weird at first but i didnt think much of it.

Now i had never met her until recently one evening. She was shopping in a mall and by chance we were at the same mall. We went to the store where she was and my bf point blank kept following her while she was shopping happily with a spark. Now i have no shame in accepting that i was jealous, bcuz everytime i went shopping with him, he would make me hurry or get distracted in his phone whilst here he was happily conversing with her and giving her opinions.

Then a few days later we all had a big get together and I was meeting his relatives aka (cousins parents) for the first time. The dinner wasnt awkward as such but i was nervous. I spoke as little as i could and even talked breifly to the cousin. After dinner we left the restaurant and the family were clicking pictures and stuff while my bf left me alone and walked away while talking to his cousin.

Usually my bf is very touchy and verbal with me around his parents and his relatives are even more chill, so I thought he would be his usual self. But on this dinner he was just talking barely to me or showing any kind of affection towards me.

So yes i dont know what to feel about this….am i just wrong?