The thing is, characters in a fictional work aren't real people, and we can't judge them and evaluate them as if they were.
In real life, all kinds of things happen that don't add up to or mean anything. That never happens in a fictional work. Everything we see, are told, aren't told, every small choice of words, it's all meaningful.
So while I agree with people like you and me, things are much more fluid and situational, they really aren't with Brian and Justin, because they exist in a world that has very different rules than the one you and I exist in.