after harry gets out of the pool, his ball boner revealed his dick to other girls who thought it was tiny
when the ball sack shrivels up and the dick hangs over it, leaving a protrusion from your pants, thus looking like a boner when indeed you do not have one
"after harry gets out of the pool, his ball boner revealed his dick to other girls who thought it was tiny" What is the definition of "ball boner"?