Prowl, this is actually good news! Now their A is out and both their spouses know about it! I would friend request his W and then keep her posted, if your WW leaves the house for him, let her know and do the same! Like all affairs, this too will fizzle out quickly. Wayward spouses have a fantasy in their head of how great their "new" relationship will be. In the end, it never works out that way.
Me: 38 W: 32 S10 D6 T: 10 (02/2004) M: 7 (12/2007) Separation 02/2015 OM confirmed 01/2015, D mentioned 12/2014 D finalized 9/2016