Affair with mother-in-law

Answer 1

This is playing with dynamite and a lighted match right next to the fuse.

The distinct possibility exist that TWO entire families will be destroyed, emotionally and financially. The Mother In Law would lose her Husband AND her children's relation ships, probably for a long long time. She would also be financially devastated as most families would side with the cuckhold Father, and give him emotional, financial, and even legal support; while punishing his wife for being a cheat.

The Son In law who cheats with her loses his wife; her daughter, and probably the support of her family AND his own family.

So, the cheating guy, much younger in this case, would be left with an older woman, no real prospects or ability to "start over" with her, AND the bitterness from both his and her families through two or more generations.

Packing up and running off 2,000 miles away might be the only way out of that mess. And, leave the MIL behind: she would be a devastated emotional and financial mess, begging the cheater son in law for cash to try and "go back" and pick up the p[ieces.

Very few people have the resources to recover from such devastation, so don't even think about it.