It's not fair. He was supposed to be her prince. Her stupid, angry, selfish prince, but he was supposed to ride with her, save her from herself and tell her when her thoughts escaped her own head and the waves washed over sanity. He was supposed to be hers.
Right now he's with a woman. Not her, never her. She hears their laughter and grunts and it makes her crazy, it makes her skin ride up against her bones and itch and chafe. She wants to be the woman, she wants it so badly that if she closes her eyes, she can taste his sweat dripping from his temple. A single drop, falling slowly and splashing into a tiny ocean onto her pale tongue.
She tells herself it's wrong, it's not her place, that she has self control, but she can't help herself from doing it.
She crawls, catlike, into her room and locks the door and reaches out. She doesn't have to look far, just beyond the cocoon of Zoe and Wash, just beyond her own head and there he is. The heat instantly rushes over her, swallowing her, and she gasps as he pushes her down roughly and she giggles when he scrapes his beard along her jaw (but that's wrong; his beard wouldn't be ticklish, it would leave her burning) and when he spreads her legs she bites her lip and cries and turns on her side, no longer participating in this particular game because even though it's easy to, she just can't forget that it isn't hers.
She just wanted to know what he was like, and now she has a scrape on her jaw for her foolishness.
Silly little girls get killed by curiosity, most often by wildcats.
She bugs Simon to bandage it for so long that he finally does, even though she hears him talking to Kaylee about her imagining it later. He's worried, but he's always worried, so what.
The next day, when she walks in on him kissing his woman long and hard outside his bunk, she simply walks over to the slut, unwraps the stupid scarf (that is such a dead giveaway for hickey hiding sweetheart, a slut like you should really know better)and pats her fingers along the harsh red beard-burn.
"You should wear this proudly"
she turns to Jayne and bows, head touching the floor, arms raised at her sides like wings, the swan's salute.
"I hereby consider our relationship terminated. Please leave your donation in the box by the stairs."
He stares after her and eventually mutters out a "gorram crazy mu gou" and goes back to probing the woman's tonsils with his tongue.
She cries.
A logical reaction, all things considered.