Pornelope 
Primal Pleasures [EPUB ebook] 

Bran and Lily don’t remember having been kidnapped as children; their only real memories are of growing up half-wild in the murky Louisiana bayou.  But now their captors are both gone, leaving them to fend for themselves. Will fiery passion flare between them as they struggle to survive in the treacherous southern swamps?
~~~~~ PG Excerpt ~~~~~
Things had been a little better before Roz had died of the fever four years ago. She’d been a lousy cook, but at least she’d tried to keep everyone fed. And Caleb hadn’t spent all his time drinking then. Plus, even though he’d never been especially nice to Bran and Lily, at least he hadn’t seized any excuse to beat them. Ever since Roz had died, they’d learn to fear the ugly sneer on his face that meant he was about to start swinging.
Three months ago, he’d staggered away in a drunken stupor after beating them nearly unconscious, and this time he hadn’t come back. Lily hoped that he’d fallen into the bayou and drowned. Bran hoped he’d gotten bitten by a whole nest of deadly copperheads first.
They lived in daily terror of looking up to see him glaring at them through the trees and reaching for his belt. The last time, he’d whipped them so hard that the bloody welts had taken weeks to heal.
It just didn’t make sense. They hadn’t been doing anything wrong…hadn’t really been doing anything at all! The swamp was always blazing hot and muggy, so they’d been running around naked, or nearly naked, for years. Why had Caleb suddenly gone nuts and started whipping them just because they’d been sunbathing on the riverbank like they’d done a zillion times before?
Was it because Bran’s sex thing had gotten long and hard? But what was wrong with that? Caleb’s always got long and hard, especially when he was watching Lily from the shadows. He gripped it in his big hand and stroked it until milky stuff spurted out, and grunted with pleasure. Then he did it again, and sometimes a third time, until it finally went soft and he staggered off to get drunk again.
Why had Caleb gotten mad because Bran had been doing the same thing himself? He hadn’t been touching Lily; he hadn’t even been looking at her! They’d just been lying together, half-asleep, and it had risen up hard and tall like a tree trunk.