Niall: He calls you 'Princess' because he once found a picture of you dressed up as Cinderella when you were younger, and he finds it adorable.
Louis: He calls you 'Pumpkin' because it annoys you. He adores the way you scrunch up your nose when you get frustrated with him.
Harry: He call you 'Kitten' after his favorite animal. He claims the way you nuzzle your face into the crook of his neck reminds him of a small cat.
Zayn: He calls you 'Darling' because in his eyes you are the most perfect thing in the world. and he wouldn't want it any other way.
Liam: He calls you 'Sweetie' because one of the first times h came home to you he found you covered in cake batter.