The War Against Gingivitis - S9-E18
Continuity mistake: At the beginning after Waldon's ex-wife video calls Waldon about Billy, Waldon goes outside to the balcony and screams. When Waldon screams, there's a cut to Alan by the sink where he also screams, breaks a plate and drops a green towel on the floor. The next cut after Alan, is Waldon coming back inside and Alan asking "Are you all right?" Look in the background and the green towel is all of a sudden folded and hanging on the side of the sink.
Chosen answer: Alan might have thought the bra was too fancy to belong to a regular woman, "I'd love to meet the girl who filled this", he says. He assumed it was one of Charlie's many women.
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