Boston Muzzle loader
When having intercourse in "doggy style" you extract the smokeless tobacco or dip from you mouth and place it into the girls anus. Then using your penis, you ram it into her anal cavity.
"Man i gave that fat bitch a Boston muzzle loader last night."
Boston muzzle loader
When you are banging a chick in the doggy style and then you put Dunkin’ Donuts coffee ground on her asshole and jam it in with your dick.
“Dude, when I railed this broad last night, I gave her the ol’ Boston muzzle loader!”