I know it’s insecurity but…

Have any of you ladies known your now spouses before you were together? When they were with other people? Long story short I know it’s insecurity but I saw my spouses ex yesterday at child support court and I can’t get her off of my mind. My first thought was, they looked cuter together than him and I do. Maybe it’s because they have a child together? Then I thought she was really his one true love. And I know he’ll ever admit it, and I don’t know why I’m so damn adamant on it, but I just feel it. He was so torn about their breakup. He had a mental breakdown and was stalking her social medias. Wanted to hurt her new boyfriends. All the angry bitter ex things he had. Now don’t get me wrong. He treats me like gold. Cherishes me completely. Everything I could ever ask for in a man. He tells me he loves me more than he’s ever loved anyone. He put a ring on my finger. But I feel like… he’s settling? He’s older. He knows I’m a good person, he knows it would have never worked with her because she is the definition of an evil manipulative slime ball. She has put us through the wringer with custody/visitation. After court he said, “when she gets a boyfriend I’m going to beat his ass cause I hate her so much but she’s a female so I’ll have to hurt him instead.” To me that screams - I still care. To him that screams - revenge for what you put me through. He SHOULD still care about her they have a child together, but to the extent of even wanting revenge? Could that just be immaturity on his part? I don’t know why I don’t believe him when he tells me how much he loves me. Past relationship trauma from my ex I’m sure.. but I just have this feeling if she became even remotely a decent person he would stay/go back/try and the love for me wouldn’t matter.