Naughty nightwear (Fallout 3)

 is a set of leopard skin pajamas found during the quest, Grady's Package, in Fallout 3.

The outfit can be repaired using various "pre-war" and Merc outfits including Pre-War Hats.

Unmarked quest: Grady's Package
A humorous side quest (actually a sub-plot to the Nuka-Cola Challenge) involving the Naughty Nightwear can be found in Marigold Metro Station, which is near Grayditch.

Bugs

 * The Naughty Nightwear's world model is bugged; when dropped, it looks identical to the Sexy Sleepwear. The All-Nighter Nightwear, however, displays an accurate world model, leopard-skin and all.
 * When you are accoasted by Lug-Nut, if you drop the Nightwear before talking to him, he still thinks you have it. Furthermore, if you "give" it to him, he'll spawn his own 100% condition copy before running off. Killing him will net you two copies of the Nightwear.
 * * When handing in the Naughty Nightwear to Ronald in Girdershade, if you managed to exploit the Lug-Nut 'drop' bug previously, you cannot hand in the quest with two instances of the Naughty Nightwear on you. Simply drop one and then talk to Ronald to complete.