Definitely think Pauline loved that edge to Derek's past, so unlike what she's used to. She's been trying to mould him into the image of her ex husband, and herself to a certain extent but the thought of Derek being rough and ready, breaking the rules has sparked an attraction in her. Will be interesting if she feels able to explore more of Derek's inner bloke!
I also think that Reg and Girls Just Wanna Have Fun was heartbreaking. I thought it was interesting that it was a song from the 80s rather than the 50s/60s. It suggested to me that as a couple they were still enjoying music well past their courting days. The message of the song and the sight of his wife flat out in the chair was in total contrast. He had nobody to dance with, nobody to share 'remember that time when...' moments with. He knows she is slipping away from him.
I'm glad they didn't have her die in that moment. For me it would have been too dramatic. The beauty of Mum is the joy and heartbreak in the small, everyday moments. I suspect she may have died next time we see them though, though i really hope not.
I don't dislike Jason for how he feels, though it is immature. He doesn't want his dad to be forgotten, or the idea that Cathy and Michael might be glad that he is dead so that they can be together. Maybe he is concerned that there might have been something between them before his dad died. Or maybe he thinks his dad might have been angry that they got together. I think he'll come round.
When Jason was talking about buying everything blue and white, she was being very Cathy-like. Not saying what she really thought, but allowing Jason his little dream. I thought that was a good touch!