Answer: A gun and a shovel
When Christian arrived to pick up Cher for their date, Mel talked to him briefly. He wasn't impressed by Christian at all, especially after Christian didn't answer appropriately when Mel asked if he drank alcohol. Just before Cher and Christian left, Mel warned him, "If anything happens to my daughter, I've got a .45 and a shovel. I doubt anybody would miss you." During their brief conversation, Mel also asked Christian, "What's with you, kid? You think the death of Sammy Davis, Jr. left an opening in the Rat Pack?" Josh decided he better go to the party with Cher and Christian to keep an eye on her.