My sister Suzie caught me

I'm Alan 29 good job and have my own house as well, still paying back the bank. Anyway last November I was home on a Saturday and feeling horny. So I got my blow up sex doll out and was getting my rocks off, when Suzie 23 walked catching me. She is the youngest of 3 and I'm the oldest, she didn't go to university like me and my other sister Karen. So she works low paid job and sometime comes to my place to borrow some money. But she usually rings before coming over, not this time however. Up to my nuts in the plastic doll when walked in looking for me. I hadn't locked the backdoor and that where came in, I don't have a dog so no notice of her arrival. Big grin on her face and I thought I was for it, with her telling everybody. But I was fairly lucky in that she wanted big cash for a secondhand car. That's why she was visiting, I'm only a block away from my parents home where Suzie still lives. Suzie is a party girl and I'm no party guy and don't do any good getting dates either. She wanted this car and it would turn out to be a good buy as it was in very good condition. $3500 was what she was hoping to borrow from me to get the car. Now she had the upper hand as they say, but she didn't try and use it against me in any sort of blackmail. but she made an offer I couldn't refuse and which was very good for me also. She would provide regular sex to me in exchange of me buying her the car. I thought it was the best offer I've had ever had concerning sex and all I could say was how long for. Three years she said a fuck every other week, as it would have taken her that long to pay be back with cash. She had always paid back all the money she borrowed from me in the past. So I agreed and she threw my doll off the and undressed and got onto bed naked. I was able to fuck her twice that afternoon and we went over to her friend's father house where the car was I paid him for his old car. He was a mechanic and said it was in as new condition and running great. Back at my place I was alone Susie was out driving her new car around for awhile. Then I heard her car pull up in my driveway and Suzie came inside and said if I wanted we could fuck, So we did she has regularly been giving me sex ever since and more than her had promised, when asked why she said getting ahead of the repayments just incase, I need to redraw to get something fixed on my car. So far I averaging 3 fucks a week and she hasn't needed anything for her car as yet. I really like fucking Suzie, the sex doll has gone to landfill.