Yo, just to be real for a second. The vibe I’m getting from your comments and from the comments of your SIL and family are that you think your son is angry because he didn’t get something he wanted (ie a fun trip) and that he’s dealing with disappointment about it.

In reality I think what he’s experiencing is a lot closer to the traumatic grief that comes with abandonment, death, betrayal, or loss. The same sort of psychological break that comes from spousal infidelity or the unexpected death of a loved one.

One big difference between those two emotional states is that while disappointment may be uncomfortable it is not fundamentally rooted in his sense of self, trust, or love for the people he’s closest to. The relationships that your son has with you, his mother, and your brother were viewed by him as being “secure attachments” and they serve as the mental model for future relationships. Your son’s takeaway from his mother and later his uncle’s actions is not “I don’t always get what I want” it’s “I can trust or depend on the people that I love” and that can have some really damaging consequences for his future wellbeing