These are ppl who have stayied freindly, and they kept this a secret for all those years from you, its safe to say they support you as a person regardless of gender.
You may have been a stelth mentor over the years to these kids as it shows anything is possible.
The negitive feelings may steam from information being hidden from you, be proud of who you are and your journey, it sounds like you can do some real good for him x