They do it together, because they've always done it together and anyway who else are they going to do it with, they none of them have any particularly close friends. So they do it together, Lucy and Susan giggling to themselves, Edmund and Peter trying to act as if this isn't such a big deal (except it is, it really is). And it winds up being Lucy who falls asleep first, cheeks pink and step slightly unsure; Peter follows shortly afterward, because he really can't hold alcohol as well as he'd like the others to think; Susan is next, an hour later, her speech only slightly slurred, which leaves Edmund to finish off the last bottle and realize he's the only one awake, and feels rather lonely because of it.