Short answers, pulled from the story.
According to a 2004 United States survey, only 13% of men wear pajamas or nightgowns for sleeping. By contrast, 31% sleep in underwear and another 31% sleep nude.
A negligee is loose-fitting women's nightwear intended to have sensuous appeal, usually made of sheer or semi-translucent fabrics and trimmed with lace or bows. A chemise is a delicate, loose-fitting, sleeveless, shirt-like lingerie garment for women, typically intended to feature a provocative appearance.
All children's sleepwear and loungewear sold in the US must comply with the Flammable Fabrics Act under standards 16 C.F.R. Parts 1615 and 1616. They must also meet the Consumer Product Safety Improvement Act of 2008, covering tracking labels, certificates of compliance, lead content limits, surface coating requirements, and phthalate restrictions.
The commission's regulations define children's sleepwear as wearing apparel in sizes 0-14 intended primarily for sleeping or related activities. Exceptions include diapers and underwear, infant garments sized for children nine months of age or younger, and tight-fitting garments that meet specific maximum dimensions.
The 1996 BBC The Clothes Show Magazine survey found that 47% of British men slept in nothing, while only 6% wore pajamas. Among British women, 37% wore pajamas and 33% wore a nightdress, with 17% sleeping nude.
A peignoir is a long outer garment for women, usually sheer and made of chiffon. It is frequently sold with a matching nightgown, negligee, or panties, making it an outer layer worn over other nightwear rather than a standalone sleeping garment.