My point is, I'm writing my own novel and I have gotten quite far, but there is a certain character in the book who is very protective but hard to read. Throughout the story he is always where his friends are, even if they are doing something he hates or is scared of.

Example: His friends are on a waterslide, and once they reach the bottom, the character (Phil) is there, and once the water accidentally splashes against him he panics because of a bad incident he had with water years ago. The main character wonders why he is there if he has a fear of water in the first place.

The reason why he is there is because he wants to protect his friends who are like family to him (because he lost his own family years ago in a car accident, falling right into a river) so he always makes sure to be keeping an eye out for them no matter what.

This character reveals his backstory eventually about his other family, but I don't know whether or not I should have him EXPLAIN why he does what he does for his friends (especially in that Example), or just let the backstory speak for itself and let the readers guess for themselves.

Hopefully this makes sense.