New to this sub, but went through something like this before.

Several years ago my spouse and I tried to be a polyamorous couple, but with strict rules that the relationships we had would ONLY ever be online. Webcams were fine, phone was fine, online was fine, but no actual physical contact.

This worked for about five months, until out of nowhere he told me I had to let him have sex with his online girlfriend or he wanted a divorce.

It was horrible and devastating and I think I spent a full day just ripping my hair out, but I knew my husband loved me, so the first thing I needed to do is figure out where this was coming from all of a sudden. Once I calmed myself down, I told him -- very calmly -- that I would need to talk to the other woman because I needed to know where her mind was with all this.

He gave me her screen name and we had a long chat. Turns out, she had been feeding him lies that our marriage was in ruins -- which it wasn't. I got the impression she'd been telling him how selfish and horrible I was, when she didn't even know what was going on in our home. She actually HAD a boyfriend whom she never intended on leaving, which meant she was not willing to commit.

So then, in a completely, oddly cordial, sort of way, I started breaking down which sex acts I was willing to allow. Because this wouldn't be a one sided relationship after all. If he was having sex with her and me, then I was in this relationship too. That's how a poly relationship is supposed to work, or at least our interpretation.

She did not like that AT ALL. She had a teensy fit at having to tip toe around "the wife."

My husband and I talked about it and decided we would give up the whole poly thing for a couple months to see if he still wanted a divorce without this woman's outside influence.

We've been married seven years since then without incident.

I don't know what rules you have set in place for your relationship, but if you could (and you think you could stomach it) I would try and contact the guy. I mean, technically speaking you are in this relationship too. I know people don't like to think about it that way, but its true.