A buttecicle is when you hit it from the back and some anal seepage leaks out, then she goes outside when it's cold and freezes into an icicle shape of seepage
Dude I hit it from behind and went outside and it so cold she got a buttecicle.
typically happens in colder climates in the winter when you have been in a bar or warm indoor climate for a significant amount of time and your butt starts to sweat. When you leave and go out side, all of a sudden you have icicles in the crack of your ass from frozen sweat.
I wanted to leave that concert so bad but now these buttsicles are making me think twice.