Some people keep their lips zipped about cheating they've seen because they don't want to get involved.
I was familiar with Eugene because the weekend before, he had propositioned me in a particularly crude manner. I realized I had two choices: tell her what kind of loathsome dirt bag she was dating, or keep my mouth shut in the hopes that she'd someday figure it out on her own.
I went with Option A. I told Gina that she could do much better than that jerk and blurted out the whole tacky tale. She was understandably upset, but appreciated my candor. I was lucky -- she dumped him, but kept me as a friend.
I barely knew Gina when I spilled my guts -- if she'd been a close friend I would've been on the phone as soon as it happened. But not everyone agrees you should tattle on a wayward partner. My buddy Erin didn't find out until years later that her husband had been hitting on her close friend, Susan. And that was only after another mutual friend spilled the beans, long after Erin and her husband had split up. The Frisky: Two opinions on outing a cheater
Most of the people I spoke with said they were reluctant to tell because they felt it was none of their business. I asked my good pal Debra if she would let me know if she saw my boyfriend making out with some other broad.
"No way," she said firmly. "That's between you, your man, and the tramp." Debra! Bad friend! The Frisky: Sometimes you've got to mind your own business.
I have been fortunate in one sense that I have never had to tell a friend that I knew of his spouse cheating. Although I think that it really depends on the situation, and how did I catch her. Personally its not my business, so it can go one of two ways either the friend is rational and understands where you are coming from... Or he can be a complete idiot and accuse you of wanting her and wants to terminate their friendship with you. So many variable can control this situation and unless you are willing to see it burn in flames you should never strike a match and spread the news.