My(26F) ex(27M) husband's new wife is using my old name.

I was married from 2018-2020. My husband cheating on me and getting caught by a good friend of ours was the final straw that made us divorce. He begged for forgiveness multiple times but I wasn't going to take him back. months after we divorced he started posting on social media with a new girl. he didn't post much but he did post enough to show he was with someone new. Then he started posting photos of him and her together and I found out that she was also using my last name. I thought it was strange but figured she had either married him, he changed her last name for her or she just liked having the same name on social media as him.<br><br>I just recently found out that they DID get married and it looks like they got married around October of last year. I also found out that he still follows me on instagram and Facebook so he knows that I still have that last name or at least he has to know I did up until now. Which brings me to why I'm posting here. Should I change my last name so I don't have to have his last name anymore? He made it very clear he wanted me to have it as he begged and begged to keep my "married name" as he called it.<br><br>I don't see the point of keeping his name. I think I've moved passed him and definitely moved on but I can't help but think he will win some kind of prize if his new wife and I have the same name? And if he knows that I have his last name and he has a new wife with that same last name that's just weird.<br><br>I have thought about changing it but I'm kinda unsure. What would I change it to? My original maiden name I had before I got married to him? It's my mothers last name and it's not a name I've really had since I was 15 so I'm not sure I want to go back to using it. My moms last name is also the last name of my fathers wife(biological parents been divorced for decades). They got married when I was 15 and I went by his last name but never legally had it. I've thought about changing it to that for some reason.<br><br>So I'm just really confused what I do about this whole name thing.<br><br>TL;DR I need help or advice on whether I should change my name or not and if so, to what.