Do your boys actually _use_ the keyhole in their underwear?

Do your boys actually take advantage of the keyhole feature in their underwear or do they just lower them out of the way when peeing? (Dad here is no help; he says that he's always just lowered the front waist band because it's easier.) I guess I'm just curious of this is really something functional or just "it's there because that's how it's always been since one-pieced union suits."