In my experience, I've found that jealousy in me has had less to do with what someone else was doing, and more to do with whether my own needs were getting met.
I think ending an interval with your wife on a sour note, followed by her going to spend time with another guy, is going to be a difficult thing to work through. It's better to get the argument resolved unless she has a prior commitment to meet with the other guy. If she's running to him solely because she wants to get away from you, then that's a problem for both of you. Polyamory emphatically doesn't work best when used as an "easy way out." Commitments and loyalty are prime considerations.
I'll say more in your other thread when it becomes visible.
Love means never having to say, "Put down that meat cleaver!"