Oh lovely!
I'll try and remember my funny ones but here my absolute worst so far:
I served a couple who, for some reason, decided to bring their dog with. Everything went well at first, took their order, took their drinks, set the table. When I took their food out the dog suddenly jumped up and bit me! It grabbed my calf and it wouldn't let go. The owners completely ignored it!!! They just sat there like nothing was going on. I was so shocked, I can't remember how I got rid of the dog, but I literally threw their food down on the table, stormed into the kitchen and told my boss she can continue serving them, I refuse to go back to their table. They didn't even apologise!
Embarrassing moments were mostly people I served who kissed me, yes, on the lips.
The best are the ones who insist you sit down and have a drink with them.