Lynne is in the back of a car. She tells the driver that a near-naked woman jumped out of a cake on her husband's birthday. The driver asks Lynne if she was not happy about it. Lynne says that she didn't mind as the scantily dressed woman was her.
It looks like Lynne is in a taxi. This is an odd conversation to share with a taxi driver given that the only other thing she has said to him is her destination. The taxi driver looks thoroughly uninterested in Lynne's conversation but realises he has to play along as she's going to tell him anyway.
So for George's birthday, Lynne jumped out of a cake akin to a stripper. For some reason, all of George's friends, which include Sammy and 'Mantha, seem to think this was a great thing to do. It may be that it was a surprise and this was how Lynne made her entrance. If that was the case, beforehand wouldn't George be really annoyed that his own wife hadn't bothered to show up to his own birthday? It's not like she does anything all day.
The woman with the bob haircut is really matching 'Mantha on the earring stakes. Later there will be evil eyes across the room and Lynne, still wearing only a bikini, will have to calm the situation.