Your W is having an affair with Roy. Accept it process it and never mention it again. Every time you do it builds you up as the adversary and bonds them together.
Be thankful that she’s having an A with a loser because once she stops running on emotions she will eventually see him for who he is as a person. There is a thread on here for a former poster “Hoosjim” if you can find it sounds similar. He eventually reconned with his W after she had an affair with a toe truck driver.
No more relationship talks and try to make yourself as scarce as possible. Your ride is just beginning and will take many months/years before it plays out.
SteveLW a vet here has stated that 90% of WWs will eventually want to reconcile. My friends parents reconciled after 35 years apart.
It certainly does help a bit that the guy is a loser and a cheap conman. It lends evidence to her mental state that she be involved with him at all.
In fact, even if there is no affair, and there is still some real, legitimate plausible deniability here, the fact that he is the company she is keeping at this point has to be because he's so morally compromised himself, he makes for a good buddy during this.
I don't even have the sort of pang one might expect out of this. If she was messing around with some tall, dark, handsome go-getter, professional type with charisma I might feel inadequate, but this guy is a clown. It's more like "okay, if that's what you want, you do you."
From the perspective of a feminist, which she claims to be, it's interesting she is spending time with someone who has not just lied to woman, but proactively and maliciously misrepresented himself to them and damaged them as a result.
