How about not presenting it as a disability, but as a personality type, and lead in with his good points maybe, like is he smart, well organized, isn't wasting his time being a social butterfly, or even just that the things he calls his "oddities" have an explanation, it's a personality type. It's makes him more real, genuine, not someone who's trying to fill a stereotype.
Maybe you've read about some of the social skills training for the people you teach and you could share it with him. There seems to be some kind of NT thing that having to learn social skills is the most embarrassing thing on earth. They should just get over it. It's ok to have to read about this stuff. Be supportive that you can hold he head up high as he learns about this stuff and the NTs will just have to deal with it.
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"Me voici donc seul sur la terre, n'ayant plus de frère de prochain d'ami de société que moi-même." Jean-Jacques Rousseau
"Do not think, 'I am alone.'" Sasaki Roshi
WonderWoman