Deuteronomy 22:5

Shall not wear — Namely, ordinarily or unnecessarily, for in some cases this may be lawful, as to make an escape for one's life. Now this is forbidden, both for decency sake, that men might not confound those sexes which God hath distinguished, that all appearance of evil might be avoided, such change of garments carrying a manifest sign of effeminacy in the man, of arrogance in the woman, of lightness and petulancy in both; and also to cut off all suspicions and occasions of evil, which this practice opens a wide door to.