Dog-in-Law 

When you marry and your spouse has a dog.

Common uses: "going to pet my in-law" "my in-law is a bitch" "my in-law wont stop humping my leg"

My wife had a dog. Fifi is now my dog-in-law.

Dog-in-Law by MicahGrot September 7, 2007

Dog-in-law 

The dog owned by your spouse's family is called your dog-in-law. (Plural - dogs-in-law)

Hey, my dog-in-law is eating your food.

My dog-in-law is super cute.

Dog-in-law by Victoria’s baby October 16, 2017

Dog Track Brother-In-Law 

A person who considers it their role to show children how the world really operates.

On the rare occasion that the children are left in the care of a Dog Track Brother-In-Law, he must be reminded that the kids can absolutely not smoke.

Dog Track Brother-In-Law by Robert Lanham, Author of Food Court Druids, Cherohonkees, and Other Creatures Unique to the Republic August 4, 2004