Ugly-Oyster
A sexual act in which a man and woman scissor legs while the man rubs his anus on the compliant female's vagina in a scissored position until climax is attained. Flatulence and defecation are usually involved as enhancements to the act.
Obsessed with filthy sex, Joanna can only climax during an ugly-oyster.
Ugly Oyster
A girl so ugly that when she gave head the first time she thought it might be her last so she kept the cum under her tongue when she was done.
A butterface is most likely one to perform an ugly oyster.