My BF keeps mentioning His Ex Gf Name 🙄

I been with my boyfriend for almost four years.. im 29 he’s 28.. he dated his ex gf (lets call her Betty) from 14 years old to 19-20 years old. So thats about 8 year ago..and hes dated other girls between me and betty.. . I feel like he mentions her name to much and its make me mad.. like if we talking about something that i guess reminds him of her hell say it and its so annoying.. let me give you some examples: today i was scrolling on pinterest and seen this cute pandora bracelet and i said to him “ i want a pandora bracelet” and then this man goes “ omg pandora bracelets are the worst thing that ever happened to me I remember i had to buy BETTY one and i had to buy one for every event, christmas, easter , her birthday” .. i said “ im not talking bout her im talking bout me” like now i dont even want the fucking bracelet anymore 😒. Another example i was talking to him about my younger brother and how when my brother was in a relationship he would do grimey shit and bring girls to the house and me and my sister would tell my brothers gf. So here he goes “ talking bout some I remember when i had some girl friends come over for a kickback and my sister told BETTY she jumped on me” and he started laughing and said it was the funniest shit ever. 🙄 like i dont wanna hear you reminisce about ur ex gf idc.. another example .. we were talking bout our old high school football field and how big it was and he mentioned how are football field was probably one of the biggest fields in the state. And he talks about how he had to go to see BETTY cheer at her school and her school field was small. He was like “ yea she use to make me come to her school and watch her cheer ugh i think she just wanted to show me off or something” like he name did not need to be metioned in this conversation..

thats just a small few examples times he mention her name dont get me wrong its not everyday but i say its more than it should be.. and whats gets me is he dated multiple girls between me and her. One girl he told me about was one of the first girls he fell in love with ( which was not betty) but she cheated and another girl he was with 2 years before he met me.. but he never mentions those girls as much as betty which im confused about. And another thing i dont like is he never says “ my ex gf” he says her actual name like she my fucking homegirl or some shit..

its like every thing I mentioned i like or want and if he brought her it when they were together he brings it up and i makes me not want to buy the shit or do the shit i was bout to do.

Please let me know if im thinking too much into it and being immature about this situation or is it really a red flag .