As Isaiah 5 v 20 puts it.

If we believe that sex is only good between a man and a woman in marriage, then any society that endorses it elsewhere is guilty of ignoring God's way. This is not a recipe for success in the long term.

The best outcome is that emotionally intense relationships are allowed to flourish, but with a clear practice of their not becoming sexualised. This provides the boy with an appropriate sense of worth without sex, which should be kept for marriage. Ideally this relationship will be provided by the father, but in many cases that doesn't happen. When that's the case, a miscellaneous 'other' adult, be it extended family or youth leader or whatever, is a good source. A bad source, that we see in gang culture, is boys finding their affirmation from gang leaders who value them for their criminal activities.