What is Congratulatio?
1.
Felatio that is congratulatory
If you win the nobel prize, you definitely deserve some congratulatio.
See
2.
Congratulations in the form of fellatio
Hey, I heard about your promotion. I gather they're be contratulatio in order.
3.
A term representing any of the many forms of oral sex, performed solely for purpose of celebrating a special occasion. Occurs most commonly in the context of stagnant, loveless marriages.
"My wife sure doesn't do the things she used to anymore. I got a huge promotion last week and still just got a kiss on the cheek that night."
"Wow, not even congratulatio?"
"Nothing."
See