That episode was very difficult to listen to, although part of me was almost glad that Rob showed his true colours again so soon after Kirsty's pep talk and after Helen had been given the second phone (good thought Kirsty!)
Did anyone else think that Rob's been hiding/moving Helen's phone again? Thus killing several birds with one stone. He gets to tell Helen off for being forgetful, makes her doubt her competance, he's the capable parent who is around when the party mum calls and Helen is unable to use her phone to speak to anyone he doesn't approve of.
I suspect that Henry wasn't badly behaved at the party at all, and even if he was would any mum of a five year old actually call the parents of another five year old to say so? I wouldn't ever call parents about a badly behaved five year old as I would (gently) handle it myself. I would however call the parents for a child that was upset and missing mum or dad. Henry is, I think, a bit on edge, as is Helen. He may have become tearful and overwhelmed at the party. I can well believe that Rob was irritated at being summoned, especially if he was spying on Helen(!) and arrived to find Henry in tears. He's the kind of person who would decide that any display of emotion was Henry "letting him down", particularly if boarding school taught him to have a stiff upper lip. He probably expects his step son to show more self control at the grand old age of five.
I suspect Helen was less willing to argue with Rob this time because Henry was in the house. Was he out last time? I don't remember him being around. I suspect that she was very conscious that Rob was in a dangerous mood, that he is capable of violence and that he had already been more abusive to Henry than ever before. I think that she was worried that if she argued with Rob, Rob would either take it out on Henry, or would be physically abusive to Helen with Henry either witnessing this, which would be very distressing for him, or the physical abuse hindering Helen's ability to protect Henry. I'm sure her priority, with a young child in the house, was to try and avoid Rob becoming any angrier.
However, I think that, for Helen, Rob has now crossed another line. He isn't a good dad to Henry, in fact he is now definitely abusing Henry as well as Helen and Helen will want to get him out of this situation.
On a lighter note I saw yellow towels on sale in Sainsburys today and thought of Shula.