I need gay wisdom

Ladies, theys and gays... I need your unbiased opinion. Let me explain:
So person 1 (female and a family member of mine) and person 2 (male) have been married for 10+ years. Everything was great until year 5 of their marriage that 1 found out 2 was cheating on her with multiple random women. She wanted to get a divorce, but 2 begged her not to, and the rest of our family except me weren't supporting her so she decided to give him another chance. But 2 was cold and refused intimacy and was being super annoying in general for the next 5+ years. Last year after so much push and pull, 2 finally said he hates "women's kind" and she's wasting her time with him. Mind you, she's a very independent and strong woman, she's never relied on him financially or anything. So she said alright and their divorce is in progress, but she seems kinda conflicted because she never got the closure she needed.

Fast forward to today, another family member of mine saw one of 2's friends (drunk af) and the dude started spilling tea about how 2 is gay and he only married 1 because he was scared that his very conservative father would cut him off. Apparently, all of his friends told him that he shouldn't ruin a good woman like 1's life but he said that his father wouldn't get off his back if he doesn't marry. And five years ago, after his father died, he realized that he's got nothing to lose and accepted his sexuality. (I assume that the sleeping around with women phase was just his denial era)
Anyway, that family member told my mom about everything, and my mom was about to tell 1 but I stopped her. I said 1 would be more comfortable hearing it from me since we're closer.

Sorry for yapping so much ╥﹏╥
Anyway, here's the main issue:
A part of me knows that 2 is a horrible person who KNOWINGLY wasted 10+ years of 1's life and made her feel lonely and humiliated; and that 1 deserves to know why she's been treated that way and get closure. But another part of me is conflicted about letting a fellow gay person be outed like this. I temporarily stopped them from saying anything, but idk what's the more ethical thing to do.
What would you do if you were me?