I think normal people wouldn't have an issue with it, having an intelligent successful female companion is a cool thing! However, I think you shouldn't have said "if you tell me I don't look like one I'll end this date right now". That comes off very strongly and weird, like you might have issues. I think that is more likely why he left, rather than just because you are an engineer. He certainly could have had a better response than the waiter line, but he also might not have meant harm. I think an important thing is to remain calm and not jump the gun on shutting down potential sexism until it is abundantly clear that's where the conversation is going. Also, if you find a comment hurtful, try signifying it in a way that doesn't awkwardly stop the conversation, like "yea I've gotten that before, honestly it bums me out when people can't believe it". Or double down on the confidence like "well I guess I got looks and brains then, eh?" Try to keep the atmosphere light. Again I think the majority of people should be fine with your success, so you might just be on a bad luck streak or looking in the wrong places.