Johnny and Robbie fight
I just now realized that Penny walked away not due to baby but because Johnny went after Robbie for baby's sake and not prior (i.e. for Penny).
Also thought it was funny that the sister didn't know the towel (item) on Robbies door meant he was with someone. When 1st saw it I thought she assumed he did it for her but she made it clear to Baby that she wanted to surprise him.