Not going to speak to what was going through people's heads in your situation (because you seem to be implying he had a sexist attitude rather than a racist one), BUT, in my own: I, a white guy, went on a date with a beautiful latina down in Florida. We went to a Mexican restaurant. When I ordered something spicy, he gave her what I believe was probably a very similar look, basically asking whether or not she thought I could handle the full spice flavor. She didn't know me that well, so just asked if I ate Mexican food often, and I said no. The waiter knew that meant not to give me the full palate, but rather the watered down 'white person version'. I don't resent them doing that at all because if it was any spicier it probably would have ruined the date. To me, it seemed like genuine concern from the waiter that I had just ordered something I would not or could not enjoy. If they routinely see certain people struggle in those situation, I don't blame them for making assumptions, even if they make them along racial lines. He helped me without embarrassing me, and I appreciate it. Instead of him calling me out and saying I would not be able to eat it, he allowed me to have that conversation with my date.

But again, there are racists and sexists out there, and I'm not trying to say your situation was the same as mine. It is just similar to something I have noticed in the past.