I was sat having a coffee with Billy. We had been best mates for over thirty years. He seemed more than a little down and when O pressed him about it he told me that his middle daughter and her husband had been trying for a baby for nearly three years to no avail. I had known Sandi since she was ten and had grown into a beautiful confident woman who ran her own business. I told him how sorry I was to hear that. Then we were onto other topics. Then a few days later Billy was having a barbecue and I was invited. All three of his daughters and families were there. I was treated like an uncle and all the kids knew me and called me uncle. During the evening I had the chance to speak with Sandi on her own and I told her I was sorry to hear her about her infertility. She made it quite clear that it wasn't her infertility it was her husbands. He was firing blanks. She said she had three lots of IVF and none of them had taken. She joked that she needed a good man and then joked someone like you. I understood what she meant as I have five very healthy children and many grandchildren. I joked that she only had to ask and I would give her a sample. Here was I a fifty one year old man offering to give a twenty four year old woman some sperm and to cap it all she was my best mates daughter. She joked that she might just take me up on that. Then we were joined by others and the subject quickly changed. A few days later there was a knock on my front door and I thought it might be one of my children visiting, but on opening the door I saw Sandie stood there. I immediately invited her in. As we sat in the kitchen she said, "About our conversation, Can I take you up on your offer. Greg is never going to get me pregnant and at twenty four I feel that time is running out." I was gob smacked. I asked was she sure, and after she said yes, I asked how Greg felt about it. He can take it or leave it came the reply. Then came the logistics, I asked how she wanted to do it and she showed me a sort of turkey baster that she had bought on the internet and explained that I load the end of it and when reassembled she would be able to squirt my offering deep in her pussy. After a bit more discussion I agreed to help. She said she could come to me or I go to her when she was ready. Then she went off to work. It was just over two weeks when the phone rang and I went round to Sandi's house and filled her baster and handed it to Greg, who I presumed did the deed for Sandi. We did it again seven more times over the three days. It failed to work and I could see the frustration in Sandi's eyes. I agreed to go through it again the following month. When I got the call I went round to her house. She was on her own as Greg was away on business. I ended up not only loading the baster but also pumping it into her sweet pussy. I did it three more times stood next to Sandi and loading the baster as I whacked off and then pumped it into her. Again no results, and again I offered to perform again for her. This time when I got the call she said she was on her way to me and would arrive in the next ten minutes. I made sure the spare bed was made up and escorted her to it when she arrived. She handed me the baster as she calmly removed her skirt and panties. I started to wank and was beginning to get into it when Sadie grabbed me by my cock and pulled me between her legs. "Just fuck me. It's the best way," she declared. Well I didn't get five kids without being a randy old sod. I was quickly inside Sadie and pumping away at her pussy. I didn't last that long and Sandie looked a little disappointed. I put that down to that she had the cum but not enough fun. As she got dressed she informed me that she would be staying for the next few days and went and got a suitcase and a box of food from her car. As we sat talking she said anytime I could get a hard on to take full advantage of her pussy and get her pregnant. It was about an hour later as we watched a film, because day time TV is rubbish, The hero was taking advantage of his leading lady. I got hard and dragged Sandi up to the spare room. This time I lasted much longer and Sandi moaned as she came, just seconds before I came deep inside her. It was later that I asked about Greg. She said she had told him it was the added pressure of him being there first time that it hadn't worked. She said he knew she was coming to me and why. I managed once more in the afternoon and as I lay in bed thinking about fucking this beautiful young woman I started to get hard again. I went into her room and we made love for quite a long while and Sandi moaned and groaned throughout our love making. It was now lovemaking and not just the actions of breeding her. We fell asleep in the spare bed. Next morning she rode my morning hard on as I played with her tits. She came just seconds before I gave her another load.That day I managed just one more load. Then as we went up to bed she followed me into my room and climbed into my bed. Her hand was straight onto my cock and stroking it. Then as it failed to get stiff she bobbed under the duvet and started to suck my cock. That was something I hadn't had in the last fifteen years since my wife died. As soon as I was hard enough she snuggled into me and I was between her legs as we were face to face. She was kissing me as I slowly pumped her pussy. It was extremely erotic having a young lady stroking my face and kissing me as I made use of her beautiful body for my own pleasure. Again we came together. Then we snuggled tighter and went to sleep with my cock still in her as it slowly shrank. I woke to another cock sucking and as soon as I was hard, which wasn't long, I fucked her doggy style. We showered together and then she said she had to go to work and left. The following month she returned and after we fucked and lay getting our breath she said she thought she was pregnant and had brought a test kit with her. She went off into the bathroom and returned a few minutes later and put the tester on the bedside table and then went down on my cock trying to get it hard again. It wasn't too long before we were fucking again. Afterwards she looked at the tester and as she smiled she handed it to me. It read Pregnant. She said she thought she was because she felt different and permanently randy. Then as we lay in bed she rang Greg to tell him the news. Over the next eight months Sandi would just turn up on my doorstep demanding sex. She said poor Greg couldn't keep up with her and near the end he didn't like fucking her while she was so big. It was a boy and other than just after the birth I saw very little of them. I suppose Sandi had her hands full with the baby and her company. I was almost two years after the birth when she turned up on my doorstep again with a suitcase. You got it. She wanted another baby. I had three glorious days and nights with her. The following month I again got to fuck her silly before se showed me the tester that said I had done it again. Those eight months were great as Sandi spent time with me saying Greg couldn't cope with her. She had a little girl. Her and Greg looked so happy with their two children in the hospital. Billy was over the moon and wanted to take Greg and myself out to wet the babies head. We dropped the boy off at his grandma's house and went on to the pub. During the boozy evening Greg talked to me when Billy was in the gents to tell me that his family was complete and that Sandi was now off limits to me. I prayed for Sandi to want a third child, but it never happened. When the first child was five they moved to Australia and sadly I only saw them once more on a visit home to Billy's. I often wonder what they turned out like and if they are well, but it is not something easily asked of Billy without him wondering why I want to know. I also wonder if some day they might tell the children who their biological father is.