Casually Exclusive 

refers to an ambiguous relationship agreement whereby both parties mutually agree to only "sleep" with each other on a casual basis, but have not made their intimate relationship publicly known. This relationship agreement is characterized by minimal or no PDA (Public Display of Affection).

In addition, the parties may go out to dinner, movies etc. They may even meet the each other's friends. And yet, the person is introduced by their first name, no last name. Neither person is bound to the other. Most importantly, there are no long, drawn out telephone conversations with each other, the phone is used merely to establish a date and time for the next meeting. Everything is in the semblance of having a relationship, minus the PDA and commitment. This agreement can be terminated at anytime.

Typically, it is established early on that one person wants to have a casually exclusive agreement, and the other party will either comply or not.
This ambiguous relationship agreement is above “f**k buddies” or “bed buddies” and is one below dating.

Sample Introduction to friends: “This is Jeremy, my friend.”

Sample Request for a Casually Exclusive Agreement: “Hey, you’re great. We have fun together, but I just don’t have the time for a serious commitment. Let’s say we have a casually exclusive agreement? Whereby, we agree to only sleep with each other – for the sake of safe sex, but let’s keep it light and casual. We can call each other when we have time, and have get together when we can. We can still go out to dinner and all that fun stuff, but I’m really not big into PDA’s. So what do you think? You game?”

Casually Exclusive by Dr. Sheldon Cooper July 16, 2009