Went to BIL/SILs on Saturday night and after finally returning from the pub to see us (wasn't drunk, just merry) he told my son (3) to call DH by a stupid nickname that he used to be called. His cousin started it, and even her little girls greet him with it in a smart tone. Then he told him to call me "mummy (nickname)", and even went as far to get him to call our baby son "baby (nickname)". I laughed it off, and told him I didn't care because it wasn't a real word but googling shows exactly what it is, and while not rude or anything I don't want to be called it! What can I do, because this will run and run now - DS called me it this evening so he obviously remembered it.