My first job was at a McDonald's. My parents made me start working when I was 14, and that was the only place that would hire me. That was almost 10 years ago, and I had a similar experience to what you described, but it appears to me that the quality of most of the chains has gotten better (at least in my area). I still don't eat there, though.
Embarrassing story: Since I was only 14, I was pretty shy when working the counter. One of my managers encouraged me to make small talk with the customers while they waited for their food, provided we weren't busy. I was helping a large woman, and mistakenly thought she was pregnant. I asked her "how long until you have your baby?" and she said "Excuse me!?!?" Turns out she was just fat. Needless to say, I don't ask women about their pregnancies anymore, unless they bring it up first. Sounds like a cliche story, but it really happened :(
Embarrassing story: Since I was only 14, I was pretty shy when working the counter. One of my managers encouraged me to make small talk with the customers while they waited for their food, provided we weren't busy. I was helping a large woman, and mistakenly thought she was pregnant. I asked her "how long until you have your baby?" and she said "Excuse me!?!?" Turns out she was just fat. Needless to say, I don't ask women about their pregnancies anymore, unless they bring it up first. Sounds like a cliche story, but it really happened :(