If it bothers you, don’t go there
My gut tells me that people who don’t approve of sexy girls purposely put themselves in an uncomfortable position by driving up to the order window along with their kids so they have something to complain about. Maybe they belong to a group who believe their moral compass is superior to others. Maybe they are not attractive and their jealousy makes them catty.
Whatever the reason, YOU are the one being a nuisance. Please stop it. The espresso stand on the next block may be the one you should visit.