My twin sister and I had never been really close until we hit puberty, the pains and problem brought us together somehow. By the time we were through the worst of it, we had become good friends.

This would probably be our last family holiday, after this year, my sister Heather and I would go our own way. Dad had booked us into a small family hotel on the south coast, for a week of sun and sand. Because money was tight, Heather and I were sharing a room again like we had before Dad had converted the attic space into an extra bedroom. I got an extensive lecture from Mum about respecting Heather privacy. The first few days were nice and hot, as was my sister. I haven't seen her undressed since I can't remember when, but she looks good in her bikini. Mum always says that the women in our family have 'childbearing hips' and Heather is definitely like that. She has a good flare to her hips and upper body, but if she turns sideways, she was very trim back to front, with no extra fat on her body. Her tits look a good firm handful and I have discovered by looking in her underwear draw that her figure is about 38 'C', 23-24 and 37-38.

We left Mum and Dad sunbathing and we wandered off to explore the dunes at the far end of the beach.

"Stay together," Mum called out after us, then "and look after your sister."

We found a gap in the fence and crawled through. The dunes looked deserted but almost immediately Heather put her finger up to her lips with a shoosh. We stopped dead in our tracks, and then I heard it too, a girlie sigh and then a male voice. Heather grabbed my hand and together we moved quietly up the next rise. Slowly we lifted our heads above the parapet and there before us was a couple making out. Heather looked at me and smiled, then her eyes locked back on the couple in front. They seemed fairly young, perhaps only a little bit older than us, the girl's top was off and he was kissing her naked tits. All of a sudden Heather's near naked body seemed very close, in fact she must had shimmied up even closer to me for we were touching along the whole length of our bodies. Feeling brave, I reached out and put my arm around her shoulders, she flashed me a quick smile and then she looked back over the dune. Slowly I moved my hand down her back and over her bra strap until I stopped at her bikini bottoms. Gently massaged her there for awhile, I noticed she was moving under my hand, slowly she was rubbing her thighs together. Taking the bull by the horns, I moved my hand lower, down to the top of her thighs. Immediately she raised her bum slightly and opened her thighs to give me better access; I could feel the heat of her arousal. My fingers soon found the right spot between her legs, a low sound escaped from her lips. I worked my fingers between my sister's legs until her head dropped on to her forearms and she came. The couple before us now forgotten, she grabbed my hand.

"Come on, let's go," she whispered.

The front of my costume was very tight as we wandered back to the main beach, by the time we arrived, things had shrunk down enough for me to walk without being embarrassed.

"Have a good walk?" Dad asked.

"Sure Dad," Heather replied, giving my hand a squeeze.

"Good, now your back, your mother and I are going back to our room for a shower and change for Lunch, what about you two?"

"Yeah sounds good," Heather said, "we'll meet you in the foyer in about an hour, ok."

Heather bagged the shower first and I lay on my bed, thinking on what had just happened.

"Your turn," she said when she emerged with a large bath towel wrapped around her. When I had finished, she was lying on her bed, with the towel still wrapped around her.

"That was so naughty," she giggled, "looking at those two and you touching me like that."

"Yeah," I said, "good though."

"Oh yeah," she smiled up at me, "I've never done that before," then after a short pause, "would you like to do it to me again sometime?" she asked from under lowered eyes.

"Sure sis," I said, "if you want."

"Yeah, please," but now we better get dressed or we'll be late." She said.

I turned my back and dropped my towel and pulled on some clean underwear, I turned then and Heather was clipping her bra strap.

After lunch we all walked about town for a few hours, doing a little shopping, Mum and Dad then left us to go back to their room for a lie down before Dinner.

"What shall we do now?" I asked.

"Perhaps we can go back to our room for awhile," she said shyly, "you know do it again."

"Sure sis," I said, my shorts suddenly tight.

I shut the door and bolted it, just to be sure that we wouldn't be disturbed, then I joined Heather on her bed where we cuddled for awhile.

"What do you want me to do?" I asked.

"I don't know," she said, "just do what you did earlier."

"Ok roll over," I said.

When she was lying on her front I ran my hands over her back and massaged her short covered rear.

"Shall I take them off?" I asked, talking about her shorts.

"Yes I suppose so," she reached under and unzipped herself.

I pulled them down over her legs, taking her knickers with them; she didn't seem to notice. Her legs opened and she lifted her bum slightly; as soon as my hand touch her thighs I could feel her heat. She buried her head in her arms and moaned every time my fingers moved over her wet pussy.