I [F18] got into an argument a couple weeks ago about my sister’s [36F] boyfriend. [mid-late 30s]. The argument started because we were talking about my 18th birthday that had passed last year.

On my birthday, I had went on a simple road trip to nice scenery with my sister, her boyfriend, and their two kids. I entertained the kids in the backseat most of the time and kept to myself, made small talk with my sister most of the time, talking about life, ect. However, did not receive even a “hi” from my sisters boyfriend let alone a happy birthday. This irked me all that time but I didn’t pay much mind to it nor did I say anything, it wasn’t that big a deal.

However when me and my sister started arguing over the phone months later, she said this was because “he’s a grown man, he doesn’t know how to talk to little girls.” This not only aggravated me but I found ironic since this man had been shit talking me and the rest of my family for no reason since I was 12. This man had problems with me even though I was practically mute at 12. So he doesn’t know how to say happy birthday to an 18 year old girl, but doesn’t have issues with gossiping about a 12 year old girl (mind you, still in his 30s at this point).

This man seems to, talk bad about my family, convince my sister into talking bad to my mother, telling my mum she cannot see the grandkids, just the most awful things you could say to your mum. And I believe he’s the cause of it. None of my other family like him because of the way him and my sister treat my mum.

To sum up, I hung up the phone on her and told her to sort out her man, and herself. AITA?