Put them on her head.

You slip the red panties over the barwench's ginger curls, leaving them perched on her head like a hat. You can't help but chuckle at the sight. It's impossible to look dignified when you're wearing a pair of underpants on your head, and the fact that they're her own underpants doesn't help matters. Plus she's tied up, of course. She looks ridiculous. She's going to hate being seen like this.

So much for that. Now for a few finishing touches.