The first clue I had that this wouldn’t be another boring summer was the second night of Nikki’s visit. I was reading myself to sleep when my bedroom door opened and an angel walked in. What other label would you give to a perfectly formed nude female body standing next to your bed? And then this lovely being asked an amazing question, “Uncle Tony, I’m horny. Can we fuck?”

That first time is a blur in my memory. Sensory overload I guess. I do remember her saying it had been five whole days since her last lay and that was WAY too long. I think she tried to make up for it right then.

I’ve been a once-a-week guy for a while, and that’s been a quickie on Saturday mornings when a neighbor wife stops by on her morning run for a dose of strange cock. Having a young, eager partner wanting at least an hour of non-stop screwing certainly taxed my physical abilities.

I’m pushing fifty, divorced for ten years. I live alone, kind of a tekkie introvert with no serious female relationship since my divorce. Nikki is the daughter of my ex-wife’s youngest sister. We always got along just fine so she called to ask me if Nikki could stay with me during a special college summer session close to where I lived. “Why not?” I thought. I remembered Nikki as a cute little nine-year-old the last time I saw her.

When the red Mustang convertible pulled in the driveway I was sure surprised. The buxom beautiful blond that got out and ran to hug me was nothing like the girl I remembered, except maybe the smile.

She awoke me in the morning for more of the same except I could pay attention to the details this time. It was lighter in the bedroom and I could see the gift I was given. Damn! I hadn’t had a piece this fine even when I was her age. Short blond hair on top, lovely blue-eyed face with sensuous lips, firm and ample breasts, flat belly, silky blond muff, long lean legs. Sexier than the porn I watched and RIGHT HERE, RIGHT NOW!

I worked hard at making it good for her and she came twice this time, only once earlier. Noisy and wiggly, no question!

We showered together and settled in for breakfast. She had to register and buy books and all the other stuff to start class on Monday. It was Friday and I offered to take her out for the evening and show her around town after dinner.

It was fun to drive her convertible. I’d never owned one but always wanted to. We settled for a casual pub and there was live music. I hadn’t danced in a decade and told her so. Nikki graciously taught me what you do to music these days. After a few beers I thought I was catching on and she seemed to be having fun. A couple of guys her age asked her to dance and I got a needed rest.

She seemed thoughtful when she joined me in bed. “What is it?” I naturally inquired.

She sat up in bed, a very distracting move since I could hardly keep my eyes from her beautiful boobs. She had a pensive look in her face as she began to relate some feelings. “I don’t think you know that the course I’m taking is about fitness in older men. You’re not ‘old’ but you are ‘older’. That first night here I was horny and never had sex with anyone more than five years older than me. I was real curious about you. I was surprised, in a good way, how good you were to have sex with. Of course I’m having a great time being with you in lots of other ways too.”

I told her how much joy she was bringing into my otherwise pretty dull life and we made rather gentle love.

In the morning Jan, my married fuck-buddy, stopped in for her usual serving of cock. I’d forgotten to mention her to Nikki so I made a quick introduction of my surprised visitor and whisked her off to my bedroom. I often just took her bent over the kitchen table so she could feel like a slut, an idea that got her off from the stuff she said while getting shafted.

I shushed her questions with kisses as I took her missionary and sent her on her run with the promise to talk to her later. Nikki was laughing at me after she left as I explained. She teased that if she knew I had any left in me she’d have taken it herself.

We talked more after breakfast. She had an idea for the required class project and would I be willing to be a subject. Since the idea was to look at the physical and mental conditioning benefits of regular sex, who would say no. I was to go to the department office Monday morning and have some baseline measurements taken for comparison with later.

Also, since more than one subject would be better, did I know any older men who might also participate? I thought of Marvin, a sixty-year old who’d moped around a lot since his wife got in care for severe dementia. I called him up and asked him to go out with us for dinner after church.

Nikki and I would go to church and see if we could find some “controls”, volunteers who matched me and Marvin but wouldn’t have any intervention for comparison. We brainstormed the study a bit and I asked, “So you would have sex with Marvin too?”

Nikki, matter-of-factly, answered, “That’s the idea.”

From the look on my face, the astute young woman went on, “Do I sense jealousy? I hope not, because that’s not the way to keep getting in my pants. I know from experience that I’ve got enough pussy to handle you, Marvin, and at least one other boyfriend.”

I interjected, “How many boyfriends have you had?”

“About half a dozen,” she replied.

I was intrigued, “So how can you tell from that?”

“That’s since the first of this year. I’ve been screwing since I was fifteen and I lost count a long time ago. As far as how often, the average is at least once a day since then. I’m not promiscuous, really. I just like sex a lot but am pretty selective about who with. Very few, like you, get me without a condom. I really appreciate getting male juices though, since they contain substances good for women. Any more questions?”

We were interrupted by Nikki’s phone. It was one of the young men from last night. He asked Nikki to go out dancing that night. She agreed to meet him there. After hanging up she explained that he was the nicest of the bunch so she gave him her number. “I need to meet some people here my own age too. I won’t be out too late. We have to go to church tomorrow.”

She was home, like Cinderella, by midnight and took a quick shower before joining me in bed. “I was all sweaty from dancing and, no, I didn’t have sex with him. It was only a first date and I’m not a slut in spite of what you might think. [grin] It did make me horny though, and you like me that way, don’t you?” YEP!

The church search worked out well and we had two more to get “measured” at school. At dinner, Marvin was as intrigued with this young beauty as I was. Like me, he needed something exciting in his life. He agreed to be in the study and would go with me to the college the next morning. I had some twinges of jealousy thinking about him between Nikki’s legs, but pushed them out of my mind. At least until I was in there myself that night.

Wise one that she was, Nikki whispered as I vigorously pumped into her, “Knowing what a hot pussy you’re getting turns you on doesn’t it?” That set me off way earlier than I’d hoped so I ate her to her finish.

Marvin and I got quite a workup the next morning. We were measured and questioned for a couple of hours, then went and had coffee.

Marvin looked at me and said, “Am I dreaming or will I really have regular sex with that gorgeous young woman to see if it improves my mental and physical fitness?”

I nodded, “You got it right. I’m already in her saddle and I can tell you it’s every bit as good as you are imagining.”

Marvin was smiling bigger than I’d ever seen, “That’s hot! I haven’t shared a woman since I was dating my wife and took her away from another guy she was dating when I met her. I never told her it was a turn on and we did fantasize a bit after we were married, but that’s all.”

I added, “Nikki wants to date guys her own age too, so there may be some more sharing, but we are in no position to complain, are we?” Marvin nodded.

Now that we were “measured”, Nikki got into her “therapy” in earnest. She was already screwing me every day and we might up that on weekends. She set up a schedule for Marvin, stopping by his place after class MWF with a weekend visit a possibility as her schedule settled down.

On Wednesday, when she returned late in the afternoon, she grinned at me and asked, “Would you like a serving of warmed up pussy?” Hell yes!

She was a little wetter than usual and I was hot thinking how it got that way. She needed release and got it. As we lay together resting, she said, “Marvin’s really out of practice. I’m glad you are here to come back to. I’m going to need that for a while, I think.”

Her young friend, Brett, texted and they went out for a short time in the evening. Her class schedule was pretty intense so she had to hit the books every evening. She studied after returning and I fell asleep.

Sometime later I awoke as she joined me. She didn’t instigate sex so I didn’t fully wake up. In the morning as we ate before she took off for class, she read my mind, not too difficult, and answered the unasked question, “No, I didn’t screw him. Just a blowjob.”

They went out Friday night. She’d fucked Marvin after class, me when she got home and it was their third date. Getting home well after closing time she showered and joined me. Reaching for my crotch, she found the expected erection and wordlessly climbed on. Neither one of us lasted long and we slept snuggled.

In the morning I was awakened by a hot mouth on my reloaded rod. This time she rode me and asked if I wanted to hear about her evening. I nodded so she continued, telling me where they went for dinner and dancing, then to Brett’s apartment which he shared with another guy. They had some drinks and she’d made it clear that she was willing to get naked.

They’d screwed twice, with condoms, before he brought her home. It had been quite a day and she’d enjoyed it a lot. There was question for me, “Now that you know what my body’s been doing, does it feel any better or worse than before?”

I thought for a moment before replying, “My cock can’t tell any difference but my mind says you are sexier than ever. Does that answer your question? I know about Marvin. Will you tell me about Brett?”

“Well. his cock is a bit thicker than yours, but he doesn’t use it as well. I’ll do him again and see how it goes.”

She settled into fucking him on Tuesday, Thursday, and Saturday. I got her most nights and all day Sunday.

With her tutelage, Marvin made steady progress in the coitus department, and his improved diet and other fitness changes gave him more vigor in many areas of his life. He was a much happier man and we became even better friends as well.

An interesting development with Brett was that his roommate was in many of Nikki’s classes. Will asked her out, knowing full well, and maybe because, she was banging his roommate, but she thought she’d better consult with Brett before accepting anything beyond them studying together.