Dean can't say shit about teens drinking, he was single digits when he had his first beer.

He's also a thirty something at a party with a bunch of teens so he likely won't stay long - but Dean doesn't get invited to do things very often, so there he stands like an awkward wallflower with a flask of whiskey in his hand, surveying the crowd.

An approachable enough guy, Dean isn't a dick unless someone provokes him to be or there's a solid reason, so chat him up with no fear before he bolts.