but if it was a helicopter week end and you were talking (knowledgeably) about piloting then it must have been fairly obvious you were a pilot.
If, as you say, he was a pilot, then he couldnt have been completely stupid, (after all he must have passed navigation, even if you can be stupid and pass air law) so he must have been taking the p***.
Now taking the p*** is definitely not sexist. I know some girls who are able to take the p*** a lot better than most men (carefully worded as not intended to suggest that one sex is any better, or should be better, or should be presumed to be better at taking the pi**).
So, I put it to you, he was doing just that, or, if he wasnt, he thought he was being clever, which he wasnt, unless of course he was fed up with people talking about flying and happened to choose you for a dig, in which case, respectfully, perhaps the whole group should have found something more interesting to talk about (says he with far too many posts on PPrUnE).
.. and so what did you say back to him?