My in laws live 2300 miles away but they know what is going on and i can tell you that their son is not welcome in their home while he is in an adulterous affair.

Each situation is different and each set of in-laws are different.

Only you know them well enough to know how to proceed.

The Bomb: 08/05
H moves out: 06/2006
H moves back: 01/07 & Out again: 01/07
H moves back: 03/08 & Out again: 04/08
H moves back: 05/09 & Out again: 07/09
Divorced 08-12
Kids: 22, 20, 19