Drinking while breastfeeding...

Twice now I have gone to a restaurant with my baby and ordered a beer and had the waiter ask me "uh, aren't you breastfeeding?"..

None of your goddamned business, kay?

Yes, I am breastfeeding, but before I go to have a drink I always make sure I have expressed milk for my son in case he gets hungry before my ONE beer is out of my system. And even if I didn't, it's not their place to question me. It IS their place to serve me what I ordered! This upset me so bad both times, why do these men, or anyone for that matter, feel they have the right to butt in to a stranger's business like that?