I’ve run into a troubling and so far very disruptive situation in my life. A long time friend has entered into a relationship with a married woman (who unfortunately is also an acquaintance and family member of another mutual friend). She often spends nights at the paramour’s house. Obviously a bad situation for him to have put himself in to begin with, but the woman’s husband is not only aware of the situation but actually approves of it.
Mutual friends have voiced their disapproval of the situation but are uncomfortably waiting it out assuming it’s a “phase” with him as he’s got a terrible history with women (his last girlfriend tried to kill him) that he usually ends up regretting later. However this has been going on for roughly two years, and very publicly for over a year, and it’s getting harder and harder to just wait out and/or ignore. They defend what they’re doing as “polyamory”. But seeing in particular as two of the parties are married I can only see it as adultery and/or polygamy.
Would an intervention be appropriate? Is it moral to simply give up on a long time friend over such an obviously immoral and frankly due to their circumstances dangerous situation? And of course what are simply the moral implications of such a twisted web?