Some folks I know can't have dairy. Lactose-intolerance. It's a thing-- and as someone who takes cooking very seriously, I tend to want to know those sort of things before I make something I hope you'll eat.

[Even if he was seen as a little eccentric, these were things he would need to consider. With a somewhat shy grin he shrugged]

Maybe it's more efficient to ask... what you don't like instead of specific things.