Etymology of the word “grephew”

Original process

Niece (Greta, Naomi, Maggie) –> Greasy Niece –> The Grease

…as in:

“Hey there, Grease!”
“How’re my Greases?”
“I need a Grease fix.”

 

Parallel process (so the boys won’t feel left out)

Nephew (Edwin, Javid, Oliver) –> (do we really need to pretend there were any steps in between?) –> “The Grephew”

“Grephew!!!!”
“C’mere and give your (uncle/aunt/biological, adopted or honorary family member) some lovin’, Grephmeister!