I have always fancied my Sister in Law. The years have gone by with an ever increasing level of suggestion and flirting. Recently I asked her at a family reunion if she had ever had an affair, she changed the subject and moved on. Last week I got a text from her asking me to come round and fix a kitchen cupboard. I grabbed my tool box and set off telling the wife that I wouldnt be too long. She open the door dressed in black and showed me to the Kitchen. The cupboard was soon mended Sarah then told me that she was very disappointed by my comment at the family reunion and said that she was going to tell her sister (my wife). I pleaded with her not to, she said that I should be punished and went on to say that her prefered way would be a sound thrashing... I had no choice but to agree. She told me to lean over the kitchen table and tied my hands firmly to the far side. She then tied my legs to the table legs. She told me to prepare myself as she left the room to find a suitable impliment. I started to become very turned on my cock stiffening in anticipation. She returned with a garden cane and placed it on the table. She then undid my trousers and pulled them to my knees followed by my boxers allowing my 7 inch cock to bounce out. I joked about her husband walking in and catching us to which picked up the cane and whacked my arse 6 times in quick succesion telling me there was no us. I gritted my teeth wiggling my bum as she gave me 6 more.This continued till I promised to behave in the future. She then asked me what my intention was asking if she had had an affair, I explained that I had always wanted to fuck her. She then stroked my balls and causing my semi erect cock to stiffen and start twitching. I asked her to untie me but she reminded me that I was here for punishment and her enjoyment. She then left the room returning with a large vibrator and some lub. The cold lub felt good as she massage my arse hole telling me that prehaps next time I would think twice about wanting to fuck her. It hurt like hell but as she pushed it up my arse my cock became rock hard as she slowly fucked me. She then put her hand between my legs pulling my cock back between my legs and wanked me till was about to spurt she then stopped and started spanking my balls very hard. I was crying with pain she stopped and told me I had take my punishment well and then she placed a bowl of iced water betwwen my legs dipping my balls and prick into the cold water to calm me down. She then dressed me, untied me and sent me home with my tool box. When I got home she texted me asking if I wanted to help with a few more DIY jobs in the future tbc