He SHOULD feel he needs to toe the line. This wasn't a one-time screw up - he has lied to Deb over and over again. It is up to him to prove and to be watched until Deb feels secure in the R - if she feels she wants to stay in it.
He's been dipping his wick in two different places. I am not sure I'd feel romantic about that, considering he may have had very recent sex with the OW...exposing Deb to possible disease and such. I really feel she should be tested for everything, just in case. I am not even sure how I'd feel being around a woman (like Deb is for work) who her husband has been plugging away at.
I do mean to sound crude - because it is. Debs husband has been screwing both of them, telling nothing to Deb but exposing Deb to this tramp....telling secrets, I am sure - that Deb never meant to leave their R. There are so many breaches of trust here, and it keeps happening.
I think Deb should go away by herself, not with H - not yet. But H shouldn't have two weeks to f*** his tramp.