I sat bolt upright in bed with a start, instantly nervous and wide awake for unknown reasons. Had I heard something? Was there a noise? I listened intently, remaining motionless, the blanket pulled up tight to my chin, held with both white-knuckled hands, was the only thing concealing my nakedness, the only protection from whatever unseen terror awaited me in the night. I listened, straining for any hint of sound, any small auditory clue as to what had brought me from sleep to wakefulness.

Glancing at the clock, the red LEDs blazed the time into my room: 2:43 am. I knew something had made a noise, something had brought me fully awake, but now all was silence. My eyes could make out the outlines of furniture from the light slanting in through the window, but nothing moved, nothing made a sound. I slid my legs from under the covers slowly, fearful of the creak of floorboards giving me away to some hidden intruder.

I slipped from the bed and snatched my robe from the hanger on the back of the door, wrapping it quickly around me and tying the sash at my waist. Though it only covered me to just below the hips, it seemed like white silk armor at that moment. Clothing is just an imaginary form of safety, yet it makes us all more secure than meeting some trespasser fully exposed.

There were no lights on in the apartment; there is always a hint of light under the door if anything in the rest of the apartment is on. I couldn't decide which door to try. Two lead from my room, one to the short hallway, the other into the master bathroom. The far side of the bathroom has another door that opens into Rebecca's room, so I choose the bathroom, thinking I could sneak through her room into the hall in case I had already made some sound to give away my location.

I moved across the cold tile on the bathroom floor, my hand reached for the doorknob that would open the door into Rebecca's room when I heard a sound beyond. Something creaked, a rusty metallic sound, as if ancient hinges had been swung open for the first time in years. I froze, my hand mere inches from the doorknob, toes chilling on the icy tile. The sound repeated.

What had hinges in Rebecca's room? I wracked my brain trying to think of what she might have in there that she could open and close with that sound, when I heard it again. Then I heard a low sound, almost a moan, something deep and resonant, not a noise Rebecca could make if she tried. I waited, then felt my cheeks burn with embarrassment when the reality dawned on me. Rebecca had brought someone home, and I, like a fool, hadn't recognized the sounds of sex in my roommates' bed.

I relaxed, my hand falling down onto the doorknob, muscles that I didn't even know were tensed unwound from their taut state of readiness. As my hand hit the doorknob, the door moved slightly towards me; it must not have been latched all the way. A crack of lighter darkness was visible between the door and the frame. I hesitated, but something made me pull the door open just far enough that I could move my eye right up to the crack and peer inside.

The room was lit by a single candle on top of the dresser. Dark mounds of clothing were scattered about the floor, and the sheets were crumpled at the foot of the bed. I had a perfect side view of Rebecca, completely naked, upright in the bed, straddling a well-muscled man I'd never seen before, slowly moving her hips up and down on him as he pushed well-timed thrusts into her. Her hands were clenching at his stomach, his hands locked on her hips. Her back arched as she rode him methodically.

I faltered, knowing I shouldn't be watching, but unable to look away from their entwined bodies, wishing I were riding that chiseled body. Excitement tingled through me like lightning through the night sky, illuminating that which lay unseen moments before. My nipples grew firm and pushed against the cool silk of my robe, warmth spread between my legs. My eyes were locked on Rebecca's naked form, drinking in the flow of her muscles, the curve of her neck, the spill of dark hair down her back, the look of ecstasy on her face.

I was aroused by the sight, but found myself staring at Rebecca rather than her partner. I wondered why I was so intrigued by her. Part of me wondered if that's what I looked like, if my body flowed in the same manner, if I got that same look of ecstatic excitement. But some other part of me was stimulated just by looking at her, by seeing her naked body, her breasts bouncing gently up and down, her long tanned legs bent around his body. I was actually excited looking at her, not him. Was it because I imagined that I was her, or because I was somehow attracted to her?

I kept my eye to the crack and ran a hand involuntarily down my body, imagining someone else caressing my breasts as my fingers moved across the smooth fabric of my robe, fingertips slowly circling my hardened nipples, sending shivers of excitement throughout me. My imagination, sparked by the scene before me, gave my hands an intangible quality. In my mind, a stranger was touching me, the man on the bed was working his hands over my body, up under my robe, his rough callused fingers spreading me open, finding me warm and wet and ready.

My finger moved between my legs and over my lips as I watched Rebecca move off the mystery man on the bed, sliding around to his side. He sat up, knelt behind her as she bent on all fours, and entered her. She sighed when he did, and I almost did, too, remembering only at the last instant that I could not be a perceptible part of this exchange. She pressed her head to the mattress, her arms spread out in front of her as he fucked her from behind, now harder, more insistent. This was not the unhurried, gentle ride of moments before, but the vigorous intensity of a man who needs release.

My fingers moved faster below my robe, stroking and tickling, sliding over the sensitive areas with increased speed, an outsider fiercely finger-fucking me with my own hands. I trembled as the onslaught continued, imagining his hands on me, his mammoth organ ramming me into the bed as he was doing to Rebecca. She was almost prone, her bottom stuck up in the air as he pounded ferociously into her from behind, her fingers clenched tightly in the sheets, her mouth opening and closing with each violent plunge, her eyes closed tight until she came, then opened in shock and awe at the intensity of her release, and her gaze met mine.

We stared at each other. Her eyes slid back and forth with his continued thrusts, mine followed the movement of her head as my orgasm quivered through my body. She raised one finger to her lips as if to say "shh," and smiled slightly, a crooked, puzzling smile, and I couldn't help but smile back, though mine was filled with nervous guilt.

Something flashed between us in that moment, some strange feeling that I still cannot identify. This was the kind of thing that could ruin a friendship, but somehow, that unfamiliar smile reassured me. I kept watching, I couldn't help it, and Rebecca didn't seem to mind, as he pulled out and spent himself across her ass, up her back. She made appropriate "ooh" sounds, but her eyes never left mine, that strange smile played about her lips, and a gleam of what almost looked like mischief flashed behind her stare.

As he lay down beside her, I backed silently towards my room. I stopped for a moment to consider what had just happened. Why couldn't I take my eyes off of Rebecca? What did that inexplicable smile mean? What was she thinking? Will she tell him? What are we going to do tomorrow, when they both come out for breakfast? How will I be able to look at either of them? I lay back down and tried to sleep, but it eluded me for hours.

Tomorrow morning will be difficult.