Why do guys get mad...

cause they're ignorant dont get me wrong there are some good ones out there but the sandwich boys need to get off their rumps make themselves a sandwich and apoligize to you for making such a rude comment

Because they're the sexist type. Don't worry, they won't get anywhere in life acting that way.

I'd be passive-agressive about it, and make them the worst sandwich ever so they'd stop asking... I think alfalfa sprouts and dijon mustard would do the trick... especially if you slap it between a couple slices of really hard bread. But, that's just me.
Actually, I'd make a carrot sandwich and tell them to eat their vegetables. You could always go the "degrading mother" route and harass them over poor nutrition!

Seriously though, those kinds of guys either straighten out by the time they're 20 or so, or else the go very long periods of time without "action" from girls.

we are not all like that, and some of us are just joking. if a guy doesnt know when or who its apropreate to make those jokes with he needs smacked upside the head really hard. there is a nerve back there that only guys havew that wakens out frontal lobe and says THAT WAS STUPID

Has that really happened?

I've only ever heard guys asking it as a joke... maybe you're being over sensitive?

no i have some friends that just don't know when to tell a joke. a girl has every right to be mad if it was said at a bad time or if the guy knows that it shouldn't have been said to that girl.

Sometimes the best way to fight stereotypes are to laugh at them... I don't see the point of getting indignant by an off-hand joke when there are people all over the world dealing with serious equality issues.