Not sure how to feel..

My SO has been struggling to get a job that actually gives him the hours he needs.. so, that’s not the problem. But today I was at work and he says his old work place called wanting him to come in Monday at 8 AM. (He worked at a nursing home.) BUT now, his ex wife is working there. And I have no idea how to feel about that. I trust him, but it just scares me. He was with her 6 years, and his whole family loves her and she still hangs out with his nanny and sister. And when we first got together, she texted him all the time. About pointless shit and we blocked her number. He says he loves me and will find somewhere else to work, but he brags about the money and all this other stuff. He said he wouldn’t work with her. She would work there too just not together. But I’m still uneasy about all this. I’m afraid this will cause a lot of drama because of her. I feel like she will say stuff to scare me I just idk. Please. Help. 😭 I just have that feeling if he goes back, something will change. And I’m so scared.