My wife wore fluorescent-colored panties during an event this weekend with a very short (for her; not that short) skirt. I convinced her to accidentally let people see the brightest panties that have ever exists. They were somewhat lacy--enough to show that they weren't swimsuit bottoms.
Mainly, it was me putting my hand on her legs and accidentally causing her skirt to rise up and legs slightly come apart, or having her sit down for a moment in place where she couldn't keep her legs together, that sort of thing.
She loved the idea, as long as it was all MY idea so she could plead her innocence.
We definitely wore out the couch when we got home!