What does he mean by "I can't help if my digits slip occasionally" in Bring It On?

In the movie Bring It On, (when they are in the car) one of the guys
says "Courtney does't wear anything under her spankies." and then he
is like "I can't help it if my digits slip occasionally" and they
start laughing. Is he talking about fingering her or something? Or
what else is he talking about? Clue me in please. Thanks!