For some reason, people don't say "Uncle In-Law". I am an "Uncle" to the children of my in-laws. Therefore, it can be awkward explaining why this uncle-ing is different to my previous uncle-ing.

I like "I am now a Blood Uncle".

It sounds totally metal.

Congratulations to my sister and her husband for the successful creation of my new niece Amelie Jane who was born yesterday, 7.06 pounds (3.2kg), cuteness factor 10.