A condition of tightness or numbness in the testicles that is felt after fully inserting them inside another person's anus for a prolonged period of time. The intensity and duration of buttballs is dependent on several factors, including but not limited to the size of one's testicles, blood pressure, tightness and dilation of the host's anus, and duration of insertion.
"Damn Tone, you dunked yo nuts in that bitch's ass for over 20 minutes! You must have a serious case of buttballs."
When a man fully inserts his penis into the anal passage (male or female) and rest his balls on the gluteus maximus thus the formation on buttballs occurs.
(Exp.1)Man George, You were so drunk last night Alex T. got in that ass so far he gave you the worst case of buttballs ever and left you a rash. Here is the picture.
(Exp.2) BITCH SHUT THE FUCK UP BEFORE I GIVE YOU BUTTBALLS!