A female student gets an over the knee spanking from a male teacher, her underwater is shown (no nudity).

Twice two girls are shown undressing one another and getting under the covers. No nudity.

A female teacher dressed as a schoolgirl is bent over a male teacher's lap and instructs him how to spank her. First over the skirt... then lifting the skirt and over the panties... then hiking her panties up like a thong and smack them cheeks... this goes on a while.

And a third girl gets a spanking, bent over a table as the male teacher hikes up her skirt, then lays some smacks... then finagling with her panties (up? Down?) while commencing rat-ta-tat smacks until a teacher charges in to stop him.