Continuity mistake: When Carrie confesses Charlotte that she is calling Aidan, the dancers moving and waving their arms wildly behind Charlotte disappear between shots. One might argue that it's because of the angle of the shot, but they're all moving around all the time and at least their arms should be visible.
Continuity mistake: When Miranda talks about her date licking her butt, the food on her fork disappears between shots.
Continuity mistake: When Aidan says he's going to the toilet, Miranda's drink is on the table, but a shot later she is drinking. Then she lowers her hand but from the opposite angle she already has it lowered.
Continuity mistake: During dance class, when the teacher says "every movement has a meaning" Carrie's right arm is down or raised depending on the shot.
Visible crew/equipment: When Charlotte shows Tray the refurbished bedroom, a squared set light is reflected on the wardrobe.
Answer: A popular brand of sexual lubricant. See http://www.k-y.com/index.jsp.
J I Cohen