This story will be more enjoyable if you read parts one and two first.
==========
Sarah handed me the vibrator. As I picked it up, I smiled back at her. "Well, that would explain what they were doing in the tent."
"Yeah, guess so," she replied. "I guess they come prepared for fun when they come to the beach. May we should try bringing toys as well."
"Well, if we do, we'll have to get a tent like them, because if we used them out in the open we're likely to get ourselves banned."
"Yeah, guess so."
I put the vibrator down and we went back out of the tent.
"So, what'd you think," Rosalynn asked with a big grin on her face, looking right at me.
"I think that's a very nice looking toy," I said, giving it right back to her. "And good for you guys for bringing it here."
"You want to see it in action?"
I looked at her, then over at Sarah, who simply shrugged her shoulders, indicating, "Why not?"
"Sure," I told her, "I'm game."
Rosalynn crawled over to the tent flap, and climbed in. I thought she was expecting us to go in there with her, and I thought it was going to be a bit crowded. But before Sarah and I could move toward the tent, Rosalynn came back out holding the Rabbit. She positioned herself on the blanket right up against our beach umbrella, sitting up with her back to the umbrella. I realized that it would be all but impossible for anyone to see her, unless they walked right up to the umbrella and tent and looked over, and with the sound of the surf nobody would be able to hear as well.
"C'mon, you two, come a little closer so you can really watch."
Sarah and I scooted over on the blanket so each of us were at one of her feet, which were spread out in front of her. I still didn't believe she was actually going to do this, I thought she was just kidding and at one point would start laughing, turn it off, and put it down. But much to my surprise, she took her index finger of the hand not holding the Rabbit and started to run it between her pussy lips. I could see that she was already wet, and her finger was spreading the wetness around her labia.
After a minute or so of this, she turned the vibrator on and gently eased the head of it into her pussy. She lay back a bit, resting on her other hand, as she did this. She pumped it in and out of her pussy slowly, and I was close enough that I could see the wetness seeping all around it, leaking out of her pussy. There was even a small pool forming on the blanket below her. I looked over at Jimmy who was sitting behind us, and he was watching her as well with a somewhat amused look on his face.
After about a couple of minutes of this, Rosalynn turned it up higher, and pushed it all the way into her. As she did this, I could see the little ear of the Rabbit was making contact with her clit, and she began to moan quietly. Sarah reached over, took my hand, and placed it on the inside of her thigh. I took this as an invitation, and began to stroke her thigh, my fingers grazing her pubes.
Rosalynn continued along, occasionally pulling the vibrator out and pushing it back in, but for the most part keeping it in contact with her clit. As her moaning began to get louder, I moved my hand further up Sarah's thigh, and began to run my fingers up and down her slit. She gasped as my fingers found that spot, and Rosalynn - whose eyes had been closed as she masturbated - opened them, saw what I was doing, and smiled in encouragement. Between watching Rosalynn, and touching Sarah, my cock was at full attention and sticking straight up.
This continued for only about three minutes more, as Rosalynn came at first slowly but then more rapidly to a boil. As she got closer to cumming, she began pistoning the Rabbit faster and harder into her pussy, leaving it vibrating on her clit for a few seconds with each stroke. As she got closer, I started massaging Sarah's labia with my fingers, spreading her own wetness that had begun to seep out of her on her lips, something that I knew she loved.
Finally Rosalynn came with a loud "Arrrrggghhh," loud enough that I thought others around us might have heard her. But as I sat up and looked over the tent and umbrella, I could see that nobody was close enough.
She pulled the vibrator out of her pussy, and I could see her juices glistening in the sunlight. There was also a very large wet spot on the blanket between her legs. She dropped it on the blanket next to her, scooted down, and lay down, eyes closed, her chest and large breasts rising and falling as she struggled to catch her breath.
Sarah took my hand and moved away from her pussy. She then started lightly clapping at Rosalynn's performance. "Well done, my girl, well done."
Rosalynn opened her eyes, smiled, and gave a small nod of her head. "Why, thank you," she said, looking at Sarah. "And what about you?"
Sarah looked at her. "What about me?"
"Would you like a go with this?"
Sarah stuttered for a second. "I couldn't. . .no, I. . .I don't think"