The top part of a nice round booty where the full butt cheeks meet the small of the back. It must jut out and fill a booty-loving man's heart with passionate desire.
Damn, look at that cute little thing with the nice curves. I just want to rest my face on that sweet butt shelf.
The crease under the butt, where the butt meets the leg.
The girl at the beach had a nice buttshelf
The bottom part of a nice ass where the butt meets the leg. There is definetly a crease. People with elongated asses that blend into their thighs don't have one.
Guys checking out a girl with a nice tight ass: Dude check out the that girl's ass. Do you see the butt shelf?
butt shelf: an implant into a girl's ass that is so high and large you can place a drink on it.
"The bar was crowded but I found a place on Acea's butt shelf to store my stella."