Twenty-something girls vs. thirty-something women - S2-E17
Deliberate mistake: In the scene at the beach party, when Carrie brings everyone beers, Miranda says "There's so much foam, I could ski on the head," but the cups are tipped toward camera and you can see there's no foam at all.
Twenty-something girls vs. thirty-something women - S2-E17
Deliberate mistake: When the girls are on the beach, Carrie's narration says "It was a sunny day", but instead it is a grey and cloudy one. Surely the filming schedule was tight and they had to cope with that day's weather.
Answer: A popular brand of sexual lubricant. See http://www.k-y.com/index.jsp.
J I Cohen