"Substitutive Toasts"

It's a way to dodge drinking with decency while pleasing both the host and other guests. If a person is a non-drinker or has already drunk excessively, but he cannot avoid another drink toasted by others for respect, he can ask someone else to cover for him, who should be his friend or relative. In a wedding, the groomsman and bridesmaid are the preferred substitutes for the newlyweds, so they need to be good at drinking.