My first girlfriend slept in nothing but panties.
Most summer evenings, following her to bed a few hours after she had gone, when she happened to kick off the sheets because it was too hot...
Most beautifully peaceful sight I'd ever seen in my life.
Unfortunately, that was in a time before consumer-grade digital cameras, and I was never one to use our Kodak.
At any rate, here's a random pic from the internets.
Took this pic of my girlfriend when she was sleeping this morning. Couldnt take off the panties tho :(