The wife steals pills from her neighbour and it is later mentioned that taking assorted pills is not new behaviour and is something she previously quit.
Fish die and they show it. They show them in the pond (you can tell, they kind of lead up to it) and then a detective holds up a bag of them later too.
Gordo says he is not married, but Simon and Robyn find dresses in his bedroom. Simon suggests it's Gordro's "spring-wear". A few minutes later, the dresses' owner is explained.
(spoilers) Not really, but you find out the main couple are related, because the adopted sister of one is the long-lost biological sister of the other.