That he called you the "roommate", means that he has a preference between you two and it's not you. If he didn't know which one of the two he wanted, you or the co-worker, then he would have used a lame ass excuse, but something he could actually still defend. Not something as obvious as thinking you can get away with calling your wire a roommate. And if he wanted you, then he would have given her the "roommate" excuse, like "she's just here to pick up papers" when she knows damn well she isn't. But he called you a roommate, while you could hear. So he wants her. It's very likely that the only reason he hasn't broken up with you, is because he doesn't want to end up alone if she doesn't want him back. But she's the one he wants.

Divorce him and move on. It is the way.

Girl, get some self-respect and leave. There’s no getting better from this.

relax, it’s just his work wife. 💀

He's gaslighting you about (at the very least wanting) to cheat on you. You are not being paranoid or unreasonable in the slightest. He's being a complete, utter, dripping ar$ehole. If he's calling you his roommate in front of her and you then he's lying through his teeth to this work female as well. Cut your losses and get out. If you stay beyond this point he'll just screw your head up so much you'll spend way too much time and money in therapy undoing his damage. Save yourself the time, cash and hurt. Dump his lying, cheating ar$e and walk the hell away. As the internet is so fond of saying: When someone shows you who they really are, Believe them.

I'd not even refer to my Girlfriend as my Roommate. Wife!? That's the one changed your status from single to married and if he could refer to you as his roommate, he doesn't love nor respect your relationship. my advice? Leave. Don't even consider it one bit

Please tell my you corrected him in front of her!

Plot twist his coworker is going through a really bad divorce right now and he just didn't want to flaunt his healthy marriage, because he knows how much the topic pains her.