Reasons
Author's Note: Accursed plot bunnies. That is all I have to say. Oh, and this takes place during Andalite Chronicles, and is spoliertastic. (And not that good. Weep.)
Author's Note, Part Two: Language now toned down slighty -- thanks, Korean Pearl! (And if you want to see the uncensored version, mosey over to animorphsfanfic ) "Why are you doing this?"

"Why?" I repeated, checking on the knots around her wrists, hoping they were secure enough.

There was no way she was letting me give her to those Yeerks willingly. She'd told me so. Repeatedly. So I tied her up.

"Well, first of all, I hate you," I said. "Thinking you're so high and mighty just because you were dumb enough to take on a few of those Skrit Na and that thing -- that Andalite -- is all over you."
"So you're jealous, is that it?" She asked, grinning like the idiot she was, convinced she'd discovered My Big Secret.
"Hardly," I said, gazing at my handiwork, enjoying the sight of her trussed up maybe a little too much.

"It's disgusting, Loren," I told her, pacing now. Wondering if maybe I'd made a mistake.

But it was too late to go back now.

"Your face?" She retorted. "Yeah, it's pretty sickening."
"Hilarious," I said. "I'm sure to laugh any minute now."

Then I stopped my pacing at looked her right in the eyes. I might as well get a few things off my chest while I still had the time.

"You have no idea how stupid you look," I informed her, "You and him practically prancing around the ship. It'd be funny if it wasn't so depressing. I mean, when we first met, I figured you had a little common sense."
She glared. "If this is your idea of sense, Chapman, I'm happy being an idiot."
"Which you are," I replied, grinning back. "I mean, let's be honest here. How do you think your little crush is going to end? At best, he's going to leave you back on Earth with no memory of all this. Who the hell do they think they are anyway, these Andalites, thinking they have the right to--thinking they're so much better than--but never mind."

I smiled and put my hand on her shoulder. "It's too bad things couldn't work out between you two. You're so damn cute together, you and your little fourlegged boyfriend. What'll the kids look like, Loren? Little blonde mutants with tails and extra sets of eyes?"

Part of me felt bad about seeing the tears in her eyes, but fuck it. The kid had to hear all this sooner or later.

I really hadn't wanted to be the one to tell her, though.

"Leave Elfangor out of this," she growled.

I leaned in closer, feeling her squirm at my touch, and whispered in her ear, "Someone had to say it."

I drew back then. "But enough about your love life," I said. "You want to know why I'm doing this? I'll tell you."
"First off, I don't want to die. These Andalites are in the middle of something big and, unfortunately, they don't give a shit about us. Elfangor and the other guy, Abron, they're all right. But stupid. They'll follow that psychopath captain of theirs to the death, probably theirs and ours -- and I'm tired of being jerked around by whatever alien decides to pick us up. The Yeerks, they're not the same as the others. They're willing to negoiate, or at least they sound more willing than these assholes we've landed ourselves with. I'm done sitting on my ass while everybody and their damn dog pushes me around. The Andalites, dad...hell, you...I'm done with that."

"And most of all?" I wondered, grabbing her by the hair and pulling her close to me.

Then I kissed her.

With my eyes closed just so I wouldn't have to see the repulsed look on her face.

"Maybe I am a little jealous," I admitted when I pulled away. "I just know I'm sick and tired of seeing you with him."

Then I opened the hatch of the ship.

It was time for me and these Yeerks to trade.