I told this Bad Service story to my sister and she nearly died of horror :p
As a set-up, I have a disability which means I'm rather weak at the knees and poor in balance (I don't fall all over the place, but I can't ride a bike, either. Ordinary walking is generally OK.)
A friend and I were visiting a seaside market held at some teeny-tiny terrace houses that are now being used as overpriced tourist trap giftshops. We went into one and were looking at their wares (little china ornaments, dreamcatchers, etc) when the woman behind the counter, seeing me clomp in sagging at the knees, said "If you're going to fall all over the place and break things, you can wait outside for your friend."
"Oh, I'm not going to fall, I just look a bit weak at the knees, I'm fine."
She snorted. "Well if you fall and break something, you're buying it, OK?"
These days? I'd have reamed her. But I was eleven at the time and my companion was only twelve... and no, I really wasn't going to fall on anything :p
Edit: when I say I was eleven, I realise this can be misleading. I was NOT touching things, falling anywhere, running around, goofing off, giggling or even speaking to my friend at the time. I was just walking and looking. That's it. And she was really quite abrupt and snappy with me...