Velma Dinkley in a very compromised position.  She's anxious to be discovered, but not so anxious to reveal the racy black undies she secretly wears to the rest of the Scooby gang.

Velma is proof that beefy nerdy girls are just as sexy as the svelte cheerleader types like Daphne.  Moreso in some cases.  I always preferred Velma to Daphne.