That’s extremely thrilling when you get to the point where you’re able to first slide your hand down her panties or when you’re able to roll her panties down.
Usually during a game of :show-and-tell” where you have just showed her yours now it’s her turn for her to show you hers.
Sometimes they still get a little shy at that point so you ask them if you can’t help, and they usually nod, and then you just slowly roll those panties down