Movies
If I have to wear a tux, she has to wear a bra.
— Paul ‧ Playing by Heart
Behind the line May contain spoilers.
Our reading
An editorial interpretation.
A grumbling bargain about fairness in dressing up: if the speaker has to put on a stiff formal tuxedo, then she must wear a bra. It's a quid-pro-quo joke where discomfort is treated as something everybody should share equally, with the two garments oddly set side by side.
Context reviewed