Characters' weird behaviour

There were so many scenes in this drama, that the main characters exhibited weird behaviour. They do act the way normal/reasonable people would. In some cases, there is total stupidity.

1. Leah's family cat is found dead in the garden. Neither she nor her husband seem that upset.
2. Adam, Leah's husband, invites Rose into their house and even gives her a glass of whisky. This is the same student that Leah has accused of cheating in her dissertation.
3. Adam meets Rose in his office and he closes the door! In this day and age, that is too risky.
4. Adam sends Rose a d**k pic from his phone! He makes matters worse by sleeping with her.Either of those could be career damagers, especially in the Me Too climate.