Going through with his plan

Okay, so maybe my perfect plan wasn't as foolproof as I had initially thought. I replayed it a few times in my head, each run-through revealing more potential pitfalls. My idea was to walk up to Lily's room, offer her the glass of water, and then 'accidentally' spill it on her sweatpants. The logic being, she'd have to take them off, and maybe then, she'd notice the mark.

But several issues popped up in my mind. What if she didn't see the mark? Or worse, what if she just got mad and kicked me out of her room? There were a lot of ways this could go south quickly.

I had to shake off these doubts. I couldn't let the fear of failure hold me back. This was just a step in the larger plan of turning Lily, my sexy stepsister, into, well, something more.

And besides, any misstep I made now would be easily forgiven once she was fully under my influence. I imagined her giving me a massage, wearing something scandalously skimpy, her hands working over my shoulders as I reclined, enjoying the view and the sensation. It was a fantasy that pushed me to take the next step.

With the plan firmly in mind, I paused at her door, gathering my nerve. I had to get this right. I took a deep breath and then knocked twice, ready to put my plan into action.

Lily's voice, muffled by the door, called out a casual "Come in."

I pushed open Lily's door and stepped into her room. "Hey, I brought you some water," I said, holding out the glass.

Her room was a typical teenager's sanctuary. Posters of bands and movie stars adorned the walls, and clothes were strewn haphazardly across the floor and bed. Her desk was cluttered with makeup and schoolbooks, a stark contrast to the meticulously organized vanity. I noticed her diary still sitting where I had seen it last, untouched and unopened, confirming she probably hadn't noticed my name.

"Thanks," Lily said, not looking up from her laptop. She was sitting on her bed, her legs crossed under her. The sweatpants I had written on were clearly visible, the fabric loose but still flattering on her figure.

As I handed her the glass, I 'accidentally' knocked it over, spilling the water all over her right pant leg. "Oh crap, I'm so sorry!" I blurted out, trying to sound as genuine as possible.

Lily jumped up in shock, the water soaking through the fabric quickly. "What the hell, Marcus?" she exclaimed, her surprise turning into annoyance. "Look what you did!"

I apologized profusely, playing up my clumsiness. The plan was working, but I had to be careful not to overdo it. "I didn't mean to, I swear. Here, let me help you clean it up."

Lily waved me off, her attention now focused on the drenched pant leg. "Just leave it, I'll handle it," she said, her tone a mix of annoyance and resignation.

Clearly, she wanted me out of the room so she could change, but a sudden idea struck me. This was my chance to take advantage of the pen's power.

"Hey! You stole my pants!" I blurted out, feigning irritation. It was a gamble, but it might just work to make her look at the tag.

Lily looked up at me, her expression shifting from annoyance to confusion. "What are you talking about, Marcus? These are my pants. I got them at Lululemon last year with Emma."

I crossed my arms, trying to look convinced of my own lie. "No, I'm pretty sure those are mine. I have a pair just like them and I can't find them. Check the tag, it should have my name on it."

Her brows furrowed, clearly thinking I was just messing with her. "Seriously, Marcus? Fine," she said, standing up. She turned around, pulling the waistband of the sweatpants away from her body to peek at the tag, and in doing so, gave me a brief but glorious glimpse of her panties. The fabric was a simple cotton, a pale blue that contrasted with her skin. It was the kind of everyday underwear that you wouldn't expect to be alluring, yet in that moment, it was incredibly so.

The way the panties hugged her hips, the elastic edging just tight enough to be noticeable but not digging in, was oddly captivating. It was a candid, unguarded moment that stripped away the usual facade of Lily's put-together appearance.

I watched, holding my breath. This was it, the moment of truth. If she saw my name, would she react? Would she suddenly accept that the pants were mine? It was a long shot, but it was the best I had.

Lily squinted at the tag, her mouth moving silently as she read. Then, as quickly as she had pulled it away, Lily let the waistband snap back against her waist, her expression shifting from frustration to confusion. Then she turned back to face me, her expression one of utter disbelief. "This... this can't be right," she stammered, her eyes wide. "Your name is on here. But how...?"

I shrugged, trying to keep my expression neutral. "Told you they were mine. Maybe you grabbed them by mistake?"

She looked down at the wet pants, still processing what she'd just seen. The situation was bizarre, but I could tell she was beginning to doubt herself. Whether it was the marker's magic or just the power of suggestion, something was happening. I couldn't help but feel a surge of excitement, mixed with a bit of apprehension about what came next.

Lily's brows furrowed in confusion, her mind clearly racing to make sense of the situation. "But I've had these for ages," she said, her voice tinged with uncertainty. "This doesn't make any sense."

I shrugged again, feigning ignorance. "Guess it's just one of those weird mix-ups," I suggested, trying to sound as casual as possible.

She shook her head, still staring at the tag. "But your name... it's right here. Clear as day." Her voice trailed off, the disbelief evident. "I'm so sorry, Marcus!"

The atmosphere in the room had shifted. Lily, usually so confident and self-assured, now seemed off-balance, her usual poise disrupted by this unexpected revelation. It was an odd feeling, seeing her like this—****, questioning.

Lily's expression shifted from confusion to a resigned apology. "I'm so sorry, Marcus. I don't know how this happened," she said, her voice a mixture of confusion and embarrassment. "I really thought they were mine."

I seized the moment, feeling a surge of authority. "Well, they're mine, so I guess you'll have to hand them over," I stated firmly, a bold demand that even surprised myself. "They are my property, after all."

Her cheeks flushed with a mix of embarrassment and surprise at my assertiveness. Hesitantly, she began to peel off the sweatpants. It was a slow, almost **** movement. The fabric slid down her thighs, revealing more of her pale blue panties and the smooth skin of her legs. The pants gathered around her knees for a moment before she stepped out of them, one leg at a time, her movements graceful despite the awkwardness of the situation.

As she bent over to pull them off her feet, her ass was momentarily accentuated, the cotton of her underwear stretching slightly, outlining her curves. It was a sight that was both unexpected and undeniably alluring. Her thighs, now fully exposed, were toned from her cheerleading routines, the skin smooth and unblemished.

Standing back up, Lily held the pants out to me, a look of disbelief still etched on her face. "Here," she said quietly, the reality of the situation seeming to sink in.

I took the sweatpants from her, feeling a heady mix of power and success wash over me. My sister, the confident and untouchable cheerleader, stood there in just her underwear and a baggy shirt, having handed over her pants to me. It was a moment of triumph, a tangible sign of the control I was beginning to exert. This was just the beginning, and the possibilities that lay ahead sent a thrill of anticipation through me.