Cousinhood - it's a word, really.

"If my mother's aunt was her father's grandmother, then that makes us…"

If you can't keep your third cousins and your first cousins twice removed straight, you are not alone. But there's a simple way to figure out the relationships between relations.

First cousins share a grandparent, 

second cousins share a great-grandparent, 

third cousins share a great-great-grandparent, and so on. 

The degree of cousinhood ("first," "second," etc.) denotes the number of generations between two cousins and their nearest common ancestor.

The term "removed" refers to the number of generations separating the cousins themselves. 

So your first cousin once removed is the child of your first cousin. 

Your second cousin once removed is the child of your second cousin. 

And your first cousin twice removed is the grandchild of your first cousin.

Clearly, it doesn't take many generations before your family tree is a bit unwieldy.

If these distinctions aren't confusing enough, first cousins can be further parsed into parallel and cross cousins. Parallel cousins are the children of same-sex siblings — for example, the children of your mother's sister are your parallel cousins. Cross cousins are the offspring of opposite sex siblings, such as your mother's brother's children, or your father's sister's children.

Don't even read that part - oy!

So . . . 

Tracy and Tia are cousins - common grandparents

Bryce and Logan are second cousins - common great grand-parents

Raegan and Logan's children would be third cousins - common great-great grandparent.

Tracy and Logan are 1st cousins once removed

Tia and Bryce are 1st cousins once removed

Bryce's children and Logans's children would be second cousins once removed

Clear as mud.  You're welcome.