One day when Fleur's not at home, Bill sits in front of her vanity and stares at the things. There are too many brushes and many, many little vials with sparkly liquids. He doesn't understand why would Fleur like any of these things. She's beautiful without them, but when he tells him that she only smiles and says make up makes her feel a little more special.
How? Bill tries and fails to understand that.
Fleur has told him about magic-infused blushes and mascaras and lipsticks, but he doesn't get it. Maybe he has to use them first to understand, like when he couldn't grasp the concept behind Gamp's Laws and Mother told him to conjure food and eat it. He is a man of action, after all.
Looking through Fleur's stuff, he wonders where to begin before remembering Ginny's attempts at make up and how she finally decided for eyeliner first. But Fleur doesn't seem to have one of those. Maybe because Fleur's things are completely magical and Ginny had to use muggle stuff.
Bill decides to use the little, tiny brush that is barely longer than half a centimeter and dips it into a vial of black goo.
He stares at it for a few seconds, daring himself to use it for scientific purposes.
Steadily, he draws a line over his left eye and analyzes it. He still feels the same. No pretty-feelings invade him. Maybe he has to do the other eye. Again, Bill dips the brush into the black goo and tries to recreate what he already did. But no.
Utter disaster occurs when his hand shakes just a little bit and the line gets crooked and thicker than the other one.
"Damn!" he curses, reaching for his wand to undo the ugly line when he hears a familiar giggle, and then a full outburst of laughter. "It's not what you think!" he exclaims at Fleur, dropping her things in the vanity and standing up.
"I'm not sure of what I think," she says still laughing. "But I'm definitely getting a Pensieve to share this with everybody!"