When someone doesn't know it's actually called lip balm, they call it lip bum. Don't ask me why they do it, they just do.
by cheesefanatic July 3, 2017
by j-oshua October 15, 2009
The rim of your anus typically with a circumference 2πr, r being the radius of the ass pussy. This has an exponential growth whether you are excreting waste, or receiving sweet love which is proportionate to each persons bum cheek volume.
by KinkyCactus April 22, 2016