sexist

My rule is that it's sexism if you would treat all members of one sex a certain way, but never any of the other sex; it's politeness (or rudeness if it's a negative treatment) if you would treat people of all sexes that way; it's flirtation if you would only treat attractive/interesting members of the appropriate sex that way.

In Seven Years of Highly Defective People, Adams points out that in one strip, nobody complained that Wally was acting like a stereotypical man.

Also, in the sunday strip where Wally stole Dilbert's lunch, and as punishment, Dilbert, anticipating the theft, had laced the lunch with female hormones turning Wally into a female. A lot of females wrote in complaining that he was implying that being female is a punishment.
Had he turned Alice into a male, absolutely nobody would have complained.

Not that I'm bitter.