A situationship is a recurring romantic or physical connection that has not been clearly defined as a relationship.
Plain English
Situationship.
The term usually describes ambiguity rather than a planned arrangement. It differs from an explicit casual agreement because the people involved may not have settled expectations about exclusivity, frequency or direction.
How it may appear in a profile
“I am not looking for an undefined situationship.”
“Our casual arrangement slowly became a situationship.”