OK, first of all, the new job is a positive development:
1) Most employers know that workplace romance is rampant and unstoppable. It is usually only an issue when it is supervisor and subordinate. If necessary they re-assign somebody. This is not a reason for H to change jobs. 2) OW is a symptom. H and OW got together due to PROXIMITY. That will be reduced. 3) A new job will be interesting, challenging, time-consuming. Less need for "changes" in the rest of his life, more need for "stability." 4) More money is never a bad thing.
Secondly, even if H hasn't read DB, don't you think he can see when a situation isn't working for him, and he needs to "act differently?" After his blow-up the other day, he felt the need to demonstrate his indifference, and his resolve to continue his current plan. He may even be blowing hot (angry) and cold (indifferent) on purpose to see how the "new you" responds.
Let him be how he wants to be. You continue to be upbeat, positive, and light. Do not ask R questions. ALSO, do NOT give ANY advice re his potential job change, because he will put the worst possible spin on it. If you suggest asking for a signing bonus, he will think you are money-hungry. If you want him to take it, he will think you don't want him working with OW. Or just plain think that you are STILL trying to RUN HIS LIFE. So, don't.
