sexuality

I'm confused.
Had a talk with my son's therapist.
I told him that son gets very angry with me when my tummy skin shows. He said it's understandable, as my son is in puberty and my skin showing is a turn-on and son is saying it's gross in order to distance himself from the arousal.
It makes no sense to me. I think this therapist doesn't know what he's talking about...
I also said to t that my dd changes clothes in the living room and I never thought much of it. So t said it's understandable this would enrage my son as well, and that I should tell my dd to change in her bedroom.
My son is 12 and it doesn't make sense to me that at such a young age he is being aroused by females naked skins.
He asked if I have brothers. I said I have a brother but I don't see him as a sexual being.
Funny how I see the average Joe on the street as a sexual being but not my own adult bro.

I got home from our meeting and was thinking about my own attraction to men, or rather lack-of-attraction to men. The image of a naked man grosses me out.
Does the average female get turned on by the male body? I don't. Does that mean I'm lesbian?

All these thoughts. Sigh.