Critical Acclaim of Realism, but Sacrifice of Morality

Well spoilers obviously for those who haven't seen it -

The nephew, Patrick, is shown to be playing two women, having at least two girlfriends, and there is not the slightest hint anywhere in the movie that that is a morally wrong thing, instead it's just portrayed as a normal teenage thing, part of who he is, part of growing up. Just there, no commentary. Now, for liberals cheating  and teenage sex may be perfectly ok under the whole "sexual revolution" thing, so for them I suppose there is nothing to argue here - but the hope remains that there are some sections of society who disagree with this sort of thing.