Messy situation

A couple months ago my ex of 10 years 39m) broke up with me (35f)I. I was devastated. He said that he felt like we lacked connection and our intimacy had become dull. We broke up but continued to live together albeit in separate bedrooms somewhat avoiding each other.

I did everything in my power to better myself including therapy, working out, being more open both sensually and emotionally. He reached out to me telling me he missed me and wanted to talk about things so I was hopeful we could work things out.

He also revealed to me some kinks that he felt uncomfortable sharing before. I also felt emboldened to share my kinks so in a weird way it brought us closer and we shared some intimate moments. I felt closer to him in that moment than I ever did in years.

It was then that he revealed to me that he left me for another woman he had been seeing before we broke up. Whether it overlapped in a physical way I am unsure but it definitely was an emotional affair. He said that she was a non-monogamous person and that he was okay with that. He also revealed that he contacted herpes from this person. Where it also is sticky is that he is her boss!

I am so confused about my feelings. He said he does love me and wants to be in a relationship with me but can only do so if we open our relationship to include him continuing a relationship with her.

I love him so much but this is such a mess and I don’t even know how to navigate this.