Good start.
Chapter two – Dad comes home early to find the babysitter and kids doing naughty things. He takes each one in turn over his knees for a good long hard bare bottom hand spanking starting with the babysitter first. The dad then spanks his kids while the babysitter stands with his nose to the wall, hands on his head, well spanked bare bottom on display.. After he spanks the kids and puts their noses to the wall he then takes the babysitter and does to him what he did to the kids.
(The mom got dropped off at the train station or something)