When Lewis is at the kissing booth Stan Gable switches girls and then starts talking to Betty. Betty says she's horney and Stan insults her and she walks off toward the tents. If you keep an eye on Bettys feet as she walks away you can see she is wearing spiked heeled cowboy ( or cow girl) boots. You can see them again seconds before she an Lewis enter the moon walk. But in the next scene, Betty steps onto the air cushions and presto the spiked heels are missing from her boots.