Ex question

So guys I have a question! I’ve been with my husband for a year now, he was married before we met but he got a divorce, but ever since the the girl has been tagging me in photos of them, still trying to get ahold of him and everything. Also his brother and sister would always call me her name. (Which is no big deal) and always compare me to her somehow. but yesterday we was having our anniversary weekend and we was just hanging out looking at our house we are buying, and all of the sudden he gets a Snapchat from his brother, I open it up because we just do that, he can open mine I open his. And it was a photo of his ex wife standing with his brother and sister, (she dared the 15 year old brother to send it.) I got all upset of course I did. He called his brother and chewed him out and his sister, they are best friend all of the sudden again, (the ex cheated on my fiancé) I’m still pretty upset and after the ex left he called his sister and chewed her out. Also called his mom today and asked about the whole

Situation of why she could be at his moms house, and the mom said she can be there whenever cause it’s his sisters friend but she wouldn’t be there if I was ever over there. Also she said they knew the ex before they did me and she wasn’t gonna be an jerk to her, pretty much taking her side! I’m just a little upset and don’t know how I should react, he was all caring last night but now he’s being an ass about it, I don’t know what I should do. She always came up in everything we do or mentioned by a family member. His sister is trying to blame me because my fiancé don’t come see them anymore as much as he use too. But we both work 12 hour jobs and are trying to do fertility treatments. I just don’t know want to do? Any advice.