Have The Dad tell his son to leave.
From Create Your Own Story
You tell the father that he needs to get the brat to leave. You let go of his mouth and he takes a deep breath before saying. "Sorry Mike. Daddy is having some trouble. Just go meet Mommy outside for me, ok?" The boy gave a quick "ok" before rushing out. After a moment you pull the father out and grab your duffle bag. You tell him to leave with you and act normal dispite the fact he is still in his tighty whitis and you are still just in swim trunks. You conseal the knife and the two of you exit though one of the back entrances by the pool. No one seemed to notice.
When you get to your car you shove him into the back seat and find some hand cuffs and cuff his hands to the front passanger seat. You close the door and drive off with your prize.
