As inspired by the other thread currently going on. People only mention sex, bit nobody mentioned love.
I know of two cases (a brother and sister). Both had short lived affairs (around three months), their family knew both were miserable in their respective marriages.
When she filed for divorce her exH recognised their marriage was done and everybody moved on quite easily, their DDs are happy and her partner moved in about 7 months ago. Her mom isn't very happy with their relationship but that's s different matter, nobody pointed fingers as to who was at fault for the breakdown of the marriage.
The brother on the other hand, didn't have the same "luck" his exW blamed the OW for everything and still does even though years have passed and she's about to get married again. She condoned her exSIL saying she was unhappy so understandably looked for it somewhere else. He has now married the OW and are expecting their first baby together. The mum is happy with this relationship but it might be that she's excited about the baby. The rest of the family seem to think they're well suited too.
I think society punishes more the OW, she's most of the times the "homewrecker", the OM seldom gets mentioned and in any case the "adulterous" wife is always to blame. Both are sexist attitudes IMO.