The summer heat clung to my skin, the kind of sweltering day that begged for the relief of a cold shower. I was sprawled on the couch, half-dazed by the warmth, when Rae dropped the news that set my pulse racing. “Phill’s coming over to use our shower,” she said casually, tossing her hair as she headed to the bathroom. “Her place is still a mess from the renovations.”

Phill, my sister-in-law, who was the quintessential good girl next door, with her shy smile and curves that hinted at desires she kept tightly locked away. For months, I’d fantasized about her, imagining what it would be like to unravel her, to guide her into a world of pleasure she’d never forget. The thought of her in our house, naked under the spray of our shower, sent a jolt of heat straight to my cock. I shifted, trying to play it cool. “What time’s she getting here?”

“Four,” Rae called from the bathroom, the sound of the shower already humming.

“Alright, I need a quick one before she shows,” I said, my mind spinning. Rae didn’t know the half of it—how the thought of Phill had me slipping into a dirty mindset, my body thrumming with anticipation.

While Rae showered, I lounged in the living room, the door cracked just enough to give a glimpse into the hall. I was naked, my cock hard as I scrolled through erotic images on my phone—pictures of women bent over, dripping, their bodies begging to be touched. I stroked myself slowly, the thrill of knowing Phill could walk in any moment making me harder. I imagined her stepping through the door, her eyes widening as she caught sight of me, her good-girl facade cracking as she watched me work my shaft.

Rae’s shower ended, and she called out, “Your turn, babe!”

I stood, my erection straining against my shorts, and made my way to the bathroom. As I passed the open area near the kitchen, there she was—Phill, standing with her bag, her cheeks flushing as her gaze flicked to the bulge I didn’t bother to hide. Her eyes lingered, her expression a mix of shock and curiosity, and I felt a rush of heat at her stare.

“Hi, Phill,” I said, my voice low, feigning surprise. “Didn’t know you were here already.” I brushed past her, close enough to catch the faint scent of her perfume, and her breath hitched, betraying her discomposure.

In the bathroom, I let the cold water cascade over me, but my mind was elsewhere. I reached into the bottom drawer of the vanity, pulling out the new toy I’d bought for Rae—a seven-inch pink dildo, still pristine in its box. I smirked, an idea forming. I hid it behind the shampoo bottle on the shelf, imagining Phill’s reaction when she found it. Would she gasp? Call out to Rae? Or would she… explore it? The thought alone had me throbbing.

I finished my shower and stepped out, yelling to Rae, “Babe, is my phone on the counter?”

“No,” she replied from the bedroom. “Check the room.”

“Damn, can you grab it for me?” I asked, knowing Phill was in the ensuite now, the shower running. I heard Rae knock on the door, her voice muffled as she asked Phill about my phone.

“Yeah, it’s on the rail,” Phill called back, her tone slightly off, like she was distracted. My heart pounded. Had she found the dildo? Had she seen the pictures on my phone—the private ones, the ones of Rae with another guy while I watched, or Rae tangled with a woman, her face lost in ecstasy? The idea of Phill scrolling through my dirty secrets made my cock twitch.

When Rae handed me my phone, I played it cool, sinking into the chair as if nothing was amiss. But my mind was racing.

Phill emerged from the shower, her hair damp, her skin flushed, and slipped outside without a word. I couldn’t resist. I crept into the bathroom, my pulse hammering as I checked the shelf. The dildo was still there, but it was warm to the touch, slick with something that wasn’t water. Holy shit. She’d used it. The evidence of her arousal coated the toy, and I couldn’t stop myself. I brought it to my lips, tasting her—sweet, musky, forbidden. My sister-in-law’s pussy juice, left behind on Rae’s new toy. My cock throbbed so hard I thought I’d lose it right there.

I returned to the chair, my mind a whirlwind of filthy thoughts. As I stroked myself, I caught a glimpse of movement—a reflection in the window. Phill, peeking through a gap in the curtain, her eyes locked on me. The thrill of her watching, of knowing she was turned on by my depravity, pushed me over the edge. I let a bead of cum spill onto my fingers, then slowly licked it off, my eyes never leaving the window. Her silhouette shifted, and I knew she’d seen it all.

Five days later, Rae and I played with the dildo, her moans filling the room as I worked it inside her. I was dying to tell her about Phill, about the secret I’d uncovered, but I kept it locked away. It was our little treasure—mine and Phill’s.

A week after the shower, I upped the ante. I attached a vibrating cock ring to the dildo and left it in the ensuite drawer before heading to work. When I got home, I checked, my heart racing. The dildo was smeared with fresh juices, the cock ring’s batteries drained. I texted Rae, teasing, “You knew I’d check, didn’t you? Left me all that tasty evidence.”

“What the fuck are you on about?” she replied, confused.

I grinned, playing along. “You taste so good, babe. Had me licking every inch of that dildo, cleaning up your mess.” I described it in detail, knowing she’d think I was joking—or maybe suspecting something else.

“If it wasn’t you, then who?” I asked, my voice teasing.

“Nobody,” she said, brushing it off.

Later, Rae mentioned offhand that Phill had been over, using our ensuite again. My mind lit up, my cock already hardening at the truth.

I knew it. Phill had been back, indulging in her secret pleasure, thinking I’d never know. I tasted her again that night, licking the dildo clean, imagining her riding it, her good-girl facade crumbling as she gave in to her desires. I wanted to tell her how good she tasted, to let her know I was in on her secret, to invite her to leave more for me. But for now, it’s our little game—her pleasure, my obsession, hidden in plain sight.