You are into him, but he's not into you.

You are into him, but he's not into you. If you haven't read the book, "he's just not into you" go buy it!

A Friendship
Not a relationship, if any suggestion of it being a relationship - it is over. 
The type where an open relationship, isn't even an option.

But the sex, that's typically not part of friendships in my book.  That's an open sexual relationship. 
Friends with benefits-okay, if we stretch the definition to a different generation. 

That has to be a very conflicting type of sex fling.  The type where the man is taking advantage of his ability to make a woman feel good.

Yes, both are grown ups and it isn't a crime.  Put me in jail if it is, because its really good, until he leaves. 

• Why?  He borrowed your car and for some reason, you cannot say no to anything when he ask. 
• Why? He keeps leaving his clothes and you keep washing them.  
• Why? He loves the way you cook.  You cook for him often.  
• Why? He comes by daily.  

You are on Cloud 9, because I mentioned the sex is really good.
You aren't looking for more, he's covering the things you need.
You understand his desire to not be committed to anyone.
You hear from others that you are the one they hear about and know he considers his 1st choice.

Suddenly, out of no where.  He's going to bring his lady to drop off something about the car he borrowed.  He doesn't want you to blow it for him, with the new girl.

What?  

When this type suddenly ends, its gonna burn and he lit the flame.