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2.
To have sexual intercourse with between a man and a woman by inserting the left or right testicle into the vigina.
I was playin Fuck A Nut last night and DAMN did it hurt!
by NutSacker July 23, 2002
 
1.
when a mans balls r inserted in a womens vagina
I was having sex with a boy last night, when a girl came and tried to "FUCK-A-NUT" me
by Mr.LeGuchie April 01, 2004