Video link: https://files.catbox.moe/a420ze.mp4
Your girlfriend was well on her way to becoming mostly pig...nothing much either of you could do about it. The pharmaceutical company was very apologetic in their email, but not in a way that would make them liable for any wrongdoing. Not even worth attempting to sue, as expected...so as the weeks went by, all you could do was watch as her humanity waned and she became something different. You didn't want to think of it as "lesser"...perhaps it was, but she was still in there. Just, less inhibited, more bestial.
You still hiked the trails at your local state park. You thought back to the first time she'd gone naked, how apprehensive she was, glancing around, worried that other hikers might see. Now, it's as if she relishes it, clambering ahead on all fours with gusto.
God...even now, that body...her smooth back, arching...the folds of her butt, and those thighs...she wasn't very "tucked in" anymore, but...even as she was now, she possessed the same allure that drew you to her in the first place. That ass was sure doin' something to you...something that might make the rest of the hike rather difficult.