Is it cold outside and you need to keep warm while you sleep? Or maybe its just going to be a day lounging around the house binging on the latest TV series from Netflix. No matter the case, Calvin Klein will keep you snug and relaxed with its nightwear options. You can choose from lounge and pajama pants to just plain shorts. There's a dash of color and some subtle patterns, but nothing too flashy because, one, it's not CK's style, and two, you don't need flash when you're sporting nightwear.