A kinky sex toy, that is inserted in the ass or the vaginal area.
yo chris can I borrow some smart balls I goig to have an erotic night with my girlfriends sister
by yo momma hoeeeeee March 05, 2009
A sexercise toy inserted into the vagina and in the shape of two balls that stimulates the vaginal muscles and causes the wearer to do her kegels all day. Feels like ticklish/pleasurable and sometimes overwhelming rumbling.
Maria can't walk because she's using her Smartballs and the sensation is too distracting.
by Rory March 28, 2005