If he's still with the OW, I say leave him be. You can do all the validating and DB principles once she's out of the picture but until then, he's just shoving both of us in his hole. (The analogy is starting to lose something X-P)
M:26 H:32 T:8yrs ILYBNILWY/ "I'm not happy": 2/6/16 D-Day-discovered PA/EA: 2/10/16 Separated: 2/14/16 He's living with OW I moved to different state: 06/16 Currently: Trying to move forward