Respuesta :
While your friend's parent are ok to give alcoholic drinks to their kids and to you, maybe your parents aren't ok with having you a drink.
You politely decline and explain that you'd prefer not to be involved with this situation and that you're not an alcohol drinker. If there is more resistance toward allowing you to exercise your right then you call a parent anyone you care about or if you came on your own you remove yourself from the situation ,