Why do girls take so long in the bath? That was the question I was asking myself as I stood crossing my legs outside the bathroom door, inside my eighteen-year-old sister was lazing in the bath while I was busting to have a pee. From downstairs I heard my parents preparing to go out as I bounced a little to control my bladder, I even managed to respond to their call of goodbye without squeaking, but as soon as I heard the front door close behind them I started to hammer on the bathroom door.

"Jesus Mary!" I yelled at the door, "I've got to go, will you open the damned door."

"All right, all right," she called back, "hold your water."

"What the hell do you think I've been doing for the past half an hour." I cried as I heard a click from the door.

Almost wetting myself I pushed the door open and rushed over to the toilet, the relief I felt when my pee jetted into the bowl was almost sexual and I gave a deep sigh of relief as my bladder stopped complaining.

"You really did need to go!" my sister laughed from behind me.

Mary was two years older than me and as big sister's go I was forced to admit that she wasn't bad, but she did have this devilish streak in her and standing there with my cock in my hand I sensed she was in one of her boisterous moods. At last my bladder was empty and I felt one hell of a lot better, flushing the loo I turned to leave the room; on my way in I had been so intent on reaching the toilet without wetting myself that I hadn't noticed anything else around me, now, as I turned, I was aware of Mary lying in the bath covering herself with an arm and a small face cloth. She grinned at me as I did up my zip, sighing I waited for her playfulness to start.

"You wouldn't be a dear and wash my back?" she grinned.

It was a reasonable enough request yet I had the feeling there was more to it, but I agreed anyway and stepped over to the bath as she sat up, still covering her interesting parts even though the rest of her was totally exposed to my eyes. As I took the soap she held out to me I felt strangely excited, rubbing the soap on her back I covered her from shoulders to the water line, putting the soap on the edge of the bath I rubbed my hands over her back to work up a good lather then rinsed it off a few moments later. Straightening I looked at Mary and grinned, I had a devilish streak of my own and it suddenly kicked in as I knelt there by the bath.

"Would you like anything else washed?" I asked tongue in cheek.

"Well, now that you mention it..." Mary laughed and picked up the soap, "you could do my...feet."

Laughing, as I knew she had ticklish feet, I took the soap and grabbed one of her ankles, giving it a tug I tilted her back in the water then ran the soap over her foot, Mary squealed and giggled as I washed her foot then squealed again when I did the other foot, water splashed over the edge of the bath as she wriggled. My shirt and trousers got soaked as a result of her wriggling yet she had still managed to keep herself covered and I grinned as I let her foot drop and stood up, Mary sat up in the bath as I took off my wet things which left me dressed in nothing but a small pair of underpants, she grinned and splashed water at me.

"Anything else?" I asked as the water soaked through my underpants.

"Well..." she grinned impishly.

God knows why but my cock suddenly went hard, the appearance of a huge bulge in my wet underpants did not go unnoticed by my sister and her grin grew wider as I sat on the side of the bath and waited for her to finish her statement.

"...I suppose you could do my boobs for me." she grinned.

If this was supposed to shock me my sister was in for a surprise, a sudden desire to wash all of her had filled me; unnatural though it may sound I was being turned on by my sister and I was enjoying the sensation. Grabbing the soap again I looked at her arm covering her large boobs.

"Well if you want me to wash them you'll have to move your arm." I grinned.

Much to my surprise and growing pleasure Mary dropped her arm without argument and sat there grinning at me as I stared at her boobs for a moment before reaching out to soap them, having covered them with the soap I put it aside and reached out to rub the soap in. My hands rubbed over her heavy globes as I lathered them up, under my palms her nipples went from soft to hard in the space of a few moments and I felt my excitement grow even more at this, for ages I rubbed and squeezed her boobs while I supposedly washed them, I even went so far as to tease her nipples in the pretext of cleaning them, Mary sighed and closed her eyes as my hands played with her tits. I didn't stop there though, rinsing off her boobs I picked up the soap and rubbed it over her chest and stomach right down to the water, only a half inch away from her pussy, Mary breathed deeply as I lathered the soap with my hands running over her body while my cock twitched and throbbed in the confines of my tight underpants.

Rinsing the soap from her body I sighed at the thought of having to stop, but something had come over the pair of us and my sister moved the face cloth from her pussy and stood up. Eagerly I soaped her buttocks then her pussy, I held my breath as I ran my hands over her bum lathering the soap and stroking her flesh at the same time. My fingers pressed into her buttocks as my excitement grew, Mary sighed loudly as she leant against the wall with her back to me then drew in a sharp breath as I ran my hand under body over her pussy, gently squeezing her pussy lips I worked the soap into a lather before running my fingers back along her slit. Using the face cloth I rinsed the soap from her backside then dropped the cloth into the water and put my hands on her hips.

"Turn around." I said softly.

Mary turned and I gazed at her pussy, her pubic hair was cropped short and concealed nothing from my view, licking my lips I lathered the soap in her pubic hair then worked my way along her pussy again, my sister sighed and glancing up I saw that her eyes were closed. As my fingers rubbed along her slit Mary leant back against the wall, the soap frothed around my fingers as I rubbed at her flesh, when I 'cleaned' her clit my sister gave a low moan that sent a shiver of delight down my spine. Once again I used the face-cloth to rinse away the soap, as I finished the rinsing Mary gave a little shudder and I smiled at the thought that I'd given her a minor climax, dropping the face-cloth I reached out and parted her pussy lips and gazed at her moist pink flesh, leaning forward I ran my tongue over her pussy and Mary gasped as a shudder ran through her. Pressing my tongue to her clit I teased it for a while before licking my way down to her hole, Mary's juices filled my mouth with their sweet flavour as I pushed my tongue into her pussy, she moaned then put a hand to the back of my head to pull me tighter to her.

"God Barry, this is all wrong," Mary groaned, "but don't you dare stop!"

I had no intention of stopping, in fact I wanted my sister out of the bath so that I could lay her down to lick her in a less awkward position, from thought to deed was but a step. She gasped as I lifted her bodily from the bath, water dripping onto the floor as I lay her back on the bath mat, a heartbeat later my mouth was back at her pussy with her hands pulling me tight to her. Mary cried out as I lapped and sucked at her, my thumb pressing at her clit adding to her delight until she gave a low squeal and began to shudder.

"Oh Barry!" she gasped out as I dug my tongue into her pussy and pressed hard on her clit.

Before long Mary was shaking so much that no matter what I did I just couldn't keep my mouth on her bucking pussy, sighing I sat back on my heels and watched her shake and shudder, my cock was throbbing in the confines of my underpants and to relieve the pressure a little I quickly squirmed out of the things. Mary's shakes were easing as I tossed my pants across the bathroom, her eyes were closed and her mouth was open as she made little gasping groaning sounds, her boobs bounced and jostled to the heaviness of her breathing, her hands lay clenching in the tuft of the carpet and her legs were bent and parted giving me an unobstructed view of her pouting pussy. The whole picture sent a thrill running through me, even had I wanted to there was no way I could control the burning lust that welled up in me and with a groan of sheer anticipation I covered my sister's body with my own, as she felt my weight come down on her Mary opened her eyes wide in surprise. Before she could speak a word of protest I was pushing my cock at her pussy, I gasped as my cock slid into her, the muscles of her pussy grasping at my shaft like a vice as I slid all the way in.