<<it is not normal for a man to fancy another man.
Just because celebrities out themselves it doesn`t make it ok to be gay>>
Sorry. That all seems a tad confused.
It isn't 'normal' to be homosexual - only a small minority of us (and many other species) are 'gay'
However, it doesn't follow that being gay is not 'ok'.
Being 7' tall isn't normal, or double jointed, or hairless but they are all 'natural' states for some people.
Your son is, like most of us, heterosexual; so homosexuality seems odd to him and that's fine. Knowing about homosexuality won't change his orientation, but if he was homosexual, observing others - especially high achievers and prominent people - would be enormously reassuring.
Most gays suffer from some sort of depression in their lives so something isn`t quite right in their heads