I ought to think of my duties to my nieces and nephews.
How many brothers or sisters do you have?
My dad and my mom allowed me to leave.
Is there a special sequence here, nieces and nephews,brothers or sisters, dad and mom?
If you don't like to deal with the sequences, try;
Brothers and sisters: siblings
My Mum and Dad:my parents
But I don't know if there is a common word for niece and nephew.
I now pronounce you husband and wife.
Have you ever heard another version, "I now pronounce you wife and husband"?
Nieces and nephews could be referred to as my siblings' children.
It is generally said I now pronounce you husband and wife. Or man and wife.