I enjoyed episode 2 but I’m finding some of the one the nose’-ness tedious.
In episode 1 we’re supposed to get the impression they presented as a perfect family, complete with a beaming DT and Kate discussing how the day had been absolutely perfect 
And in ep 2 we have sinister, abrasive DT.
I know the point is meant to be that things aren’t always as they seem, but I think they could have been less didactic in the storytelling in places.
Someone said earlier they didn’t trust Kate’s GP as he came across odd: I agree but I think that was just bad acting or directing or writing, or all of the above. His lines were a bit duff.
The actress who plays Kate, Anna Madeley, is wonderful and I think her parts are especially nuanced. Her scenes with DT are great. They catch that marital tension and harshness and disappointment, that could be a snapshot of irritation from built-up resentment, or indicative of something much darker.