When fornicating with a member of the opposite sex (or not depending on preference) one slips one's nuts into the action to create a lovely FruitBowl. Also see Mudbowl, similar to a Fruitbowl but the completed package of sweaty love is inserted into the anus rather than the vaginal opening
"My dear you look a trifle flushed, have you been fruitbowling it again?" enquired the First Earl of Chester of his chambermaid
"Why yes m'lord" she replied "most enthusiastically m'lord"
"Excellent" he replied "then you won't mind me slipping you a mudbowl"