I like a bunch of the ideas above BUT I personally would love to see more humiliation included with her panties. Some teasing if they're more granny style or still teasing if they're pretty skimpy, and if she wants to show off her ass they're gonna help her, and this can introduce the taunting of a wedgie and then spanking, and maybe even some laughing and speculation on how it sounds like she likes getting her panties rammed up her ass and her butt spanked. 

The teasing is so underrated and you do it so well! 

Also, I dont know if I've seen this yet but... perhaps they drag her to the bathroom and we see a gif of her head going into a toilet, aka a swirly, and then boom, pansted next slide, and then a spanking of wedgie. Though that might be too much? Eh just thinking out loud