adultiversary

The annual recognition of the date that two people, at least one of whom is married, began their extramarital tryst.

Jack and Jill have been married for ten years, but Jill is about to celebrate her three-year adultiversary with her sancho Matt.

by Anon21412 May 20, 2014

adoptiversary

combined from adoption and anniversary...used to to denote the anniversary of adopting a kid or a furkid.

Often celebrated like a birthday.

Tomorrow is me and Fido's adoptiversary...it is 3 years since I picked him up at the shelter

by daveholman May 1, 2009