Having been an active member of NCT tea-groups with all 3 kids I have seen various gaffes and suffered embarrassing humilations at the dreadful behaviour of my own children. These include:
dd1 projectile vomiting over tea-host's new sofa (she was a mere 3 months at the time, but I didn't know the hostess lady at all, who made it worse by immediately removing the covers off the sofa in the middle of the group so she could get them in the washing machine. - trying to make me feel REALLY bad??)
An evil toddler supposedly coming over to kiss ds, a mere babe in arms at the time. As she approached his face her jaws opened and she bit him with the ferocity of a pit-bull. As I pulled her off while ds screamed for his life, toddler's mum merely sighed, raised her eyes to heaven and said, "Tsk, she's ALWAYS doing that."
And finally, the time I walked into a kitchen of someone else's house to find a mum snogging a stay-at-home dad, and no, they weren't married to one another!! Their children were busily knocking the sh*t out of each other in another room and I had come to ask them to intervene!
Dying to hear all sorts of stories of bad behaviour from others.....