Oh come, all ye faithful - S1-E12
Continuity mistake: The second time Miranda has sex her arm is under the man's armpit in one shot, but over his arm in the other. (00:01:12)

Oh come, all ye faithful - S1-E12
Continuity mistake: After Miranda has had sex, her green sheets change to grey.
Answer: A popular brand of sexual lubricant. See http://www.k-y.com/index.jsp.
J I Cohen