A Dib Stick is when someone forms their finger into a nuckle and penetrates it into the anal region of someone’s body causeing an immense sensation of both pleasure and pain.
When at the beach, sand is lodged underneath the foreskin of the penis and gets stuck.
"Dave was skeptical about visiting the nudist beach; when he heard about how John got a sandy dib-dab last time.
"Bob decided never to try sex on the beach again as he had to deal with a sandy dib-dab"