Do you change your style of underwear for each occasion?

My buddy wears different styles of underwear in different situations...for example, at the gym = jockstrap, at home = boxers, formal wear = boxer briefs and board shorts = briefs. Personally I am a tighty whitey brief guy 24/7 no matter what I wear on the outside. What about you? Do u stick to one style of underwear or switch depending on the situation?