This was a dilemma.
Not only did you lose your girlfriend's anniversary present, but apparently this particular present possessed magical properties that changed your lower body into the oppisite sex, from your middle to your toes. Worse yet, the present wasn't the most important thing you just lost.
There was a pussy between your legs. According to the description the change had become permanent the moment you'd washed the pantyhose off your legs with some warm water.
Covering it up seemed like impossible. You hadn't grown any shorter, since the pantyhose fit right over your legs when you'd put them on. Instead, your now feminized proportions had shifted to adapt to your masculine upper body. Your hips and ass now stuck out from below your torso like they would below a woman's shapely frame as well.
Another knock on the door shook you out of your reverie. Sadie was growing impatient, and you had to explain to her just why you invited her in empty-handed. "I'm coming!" you shouted.
You quickly rubbed yourself dry with your towel, missing some of the harder to reach places, and lastly carefully dabbed down the new plumbing between your legs. You had to hurry downstairs, so you quickly put on your jeans, not thinking much of it, only to run downstairs and feeling its seam rub against your sensitive sex. You couldn't think about it for long enough to wonder whether it felt nice or uncomfortable. You'd have to put on a belt as well. Although your jeans didn't slide off, they felt loose around your waist.
"Happy 1 year anniversary babe!" Sadie celebrated. She dove forward to grab you, and you felt her legs hook you around your waist, her entire weight suddenly assaulting your newly transformed, and evidently less muscular legs. You struggled to hold her, and only managed to do so after taking a couple of steps back to regain your balance. You felt a jolt coming from your groin again as the seam of your jeans shifted against it.
For a moment, you just wanted to forget your demise, so you passionately kissed your girlfriend on her lips. The small and exciting jolts became a gradual flow of arousal and pleasure as a consequence. It turned out that Sadie had been looking forward to meeting you as much as you did.
When you finally forced yourself to break the kiss, and set her down on her own two feet again, you were already out of breath, and your legs were shaking.
Only so long before she figures it out herself, you realized.
"Babe," you began, "I've got to tell you something."