Two And A Half Men: Season 2, Episode 18

2 - 18: It was 'Mame,' Mom

Charlie is invited to a party hosted by a gay ad-executive named Eric, so Charlie asks Alan to pretend that he is his life partner. Charlie then meets Eric's gorgeous ex-wife (Lucy Lawless) who doesn't believe him when he claims he is straight. Charlie then returns home to find out that Eric had tried to hit on Alan. Title quotation from: Charlie, correcting his mother as to which play he dressed up as characters in as a child.