Is it wrong to refer to infants as "crib monsters"?

In jest, I referred to my new born niece and nephew as crib monsters to my sister-in-law at a family gathering yesterday night. I of course love my niece and nephew to death, and meant nothing but love, but my sister in law became very upset and left the dinner table to go upstairs to cry. I was taken aback by the... show more In jest, I referred to my new born niece and nephew as crib monsters to my sister-in-law at a family gathering yesterday night. I of course love my niece and nephew to death, and meant nothing but love, but my sister in law became very upset and left the dinner table to go upstairs to cry.

I was taken aback by the situation, and my mother and brother were not amused and told me I was being very insensitive and began to chide my for not settling down and having kids of my own. Am I really in the wrong?
15 answers 15