I would have to agree, with this response above… assuming that you are a cuck.
Perhaps on a HotWife scenario where part of the kink is watching your wife with another man, tho gs might be different.
But for a cuck relationship, I think that your wife fucking without you is a natural progression. Much like holding g hands leads to kissing and kissing leads to fucking, once your wife enjoys another man and you, as the cuck, enjoy that she did it…. Soon she might spend several hours alone with him… then overnight… then, possibly an extended out-of-town vacation.
It’s how it went for us, and as I said, for a cuckold relationship, a natural progression.
It’s something that you just have to learn to accept.