Their relationship can't be that bad if they're sneaking off to have sex at their therapist's.
...what other reason is there for Dinah to have left her zip undone?
(I always consider Dinah to be middish thirties right now with a much younger body after the Lazerus Pit incident. She's twenty years younger than Ollie, who I',m sure can't be above his fifties, even if he did lose ten physical years under Smith's pen)