Cosplationship 

When two mutual friends consistently cosplay characters in romantic relationships, even if one or both of the friends is in a relationship with a significant other.

A: So X and Y are cosplaying Hungary and Prussia, Eridan and Feferi, Sakura and Sayoran, and Faust and Eliza? Are you sure they're not dating?
B: Nope, they're just in a cosplationship!

Cosplationship by blueskiesforme January 27, 2012

covlationship

A relationship that started during Covid that will not make it out of Covid.

Dude this girl is perfect for a covlationship.

covlationship by zubber December 16, 2020

Copulationship 

a sexual friendship. A friendship where sex is the basis for a friendship or a friendship that evolved from an purely physical encounter. friends with benefits

What began as a booty call, evolved into a satisfying copulationship among the circle of friends..

Copulationship by Graciebaby March 2, 2009