I usually intend to hate these "what do men really like" articles, because I don't believe that men are that thoughtful in their life ;) Also, men are individuals too, so it's hard to define a stereotyped preferences of them as well as it is impossible to convince a woman just wearing and doing what a man would like.
However, in recent blog post, tv shows, books AND newspapers, journalists taught me which nightwear men really want to see on girls.
Yes, men like it when women wear men's shirt during the night. No sexy and expensive lingerie or a beautiful negligee, just a plain man's shirt. Until now I haven't found a serious source which explains why men like it so here is my own theory: I think it is the mixture of a man's items on a female body. Men feel emotionally and physically connected to their shirt and seeing this masculine item on a the softer female body seems to be sexually stimulating.
So this might be helpful when you wake up with your boyfriend and you want to attract his attention. However, if you don't like man's shirt then, hey, be your own personality and wear what ever you would like to!
I wish you a wonderful day!
All the best,