A few years ago a relative told DH he had a one night stand with a stranger when his wife had only just given birth to their first child. He didn't seem remorseful, he was if anything talking in a 'boastful' way. DH was angry and gave him a lecture on what a t**t he was being and they had a bit of a fall out over it. The wife was never told and doesn't know.
Things thawed slightly and we see the family now and again, although we're not close anymore. However things have been said by mutual friends and DH has witnessed something himself that suggests this man is a serial cheater and it wasn't just a one off. We are both pretty disgusted by this - he has a lovely wife & children and he seems to not give a toss that he's putting all that at risk.
So what do we do? Are we being as bad as him by sitting back and saying nothing or is it none of our business? We struggle to be around them when it winds us up so much, but does that just man we should keep our distance more?
She seems completely oblivious and happy, which makes it worse in a way.
So when do you tell and when do you keep out of it?