It all started 7 years ago when I started dating Michelle who would later become my wife. Her sister Becky is a lovely girl, a little on the chubby side but with massive tits and very flirtatious. We were at her house one day and id gone to the toilet. As I was walking passed her room the door was open and I glanced into her room to see her standing there looking into to a mirror with just a bra and knickers on. I stopped for a quick look and carried onto the toilet with my cock starting to twitch. When we left later I had left my phone on the chair and went back to get it. As I picked up my phone Becky turned around and asked if I enjoyed the view and said I could have her anytime I wanted. Now if I was single I would have been in there straight away but I was dating Michelle and consider myself pretty loyal to the person I'm with or so I thought. 

For the next couple of years Becky would flirt with me but I would always turn her down. Then it happened. 

She messaged me one Thursday morning asking if I could take a look at her laptop as she needed it for work purposes and couldn't get it to connect to the internet. It was my day off so said I would come down. About an hour later I turned up. I went into the living room and she showed me the laptop. I took it off her and she went out of the room. About 5 mins went by when she came back in. Wearing only a nice matching black knickers and bra set. I couldn't take my eyes off her tits as they were bulging to get out of her bra. She casually took the laptop off me and could see the bulge in my pants and I knew it was going to happen. 

She straddled me on the sofa with her tits about level with my face, my hands reached behind her and undid the clasp on her bra and got her tits out. I slowly started to suckle on both her nipples and she was starting to moan as my tongue went to work. I knew I was in to deep now to back out, we started kissing and she turned and said I want your cock now, she got off me and I proceeded to take off all my clothes and I sat back down on the sofa, where she got between my legs and slowly started sucking on my cock, looking at her tits moving about I knew I wouldn't last long so I stopped her and said I would return the favour. Taking off her knickers I went down between her legs, she was so wet down there and I loved tasting her moist pussy and could have stayed there for hours but she was begging me to fuck her. 

We moved onto the floor and I got on top of her, sliding straight into her she came pretty much as soon as I put my cock in her. We fucked in a few positions till I couldnt hold back anymore and came deep inside her. 

After a few minutes she went upstairs and got a blanket down and we cuddled up on the sofa. We chatted for a bit then I said I had to leave and we really shouldn't do that again. She looked a bit disappointed but asked if she could give me a blowjob as she wanted to taste my cum. Who was I to say no, she took my flacid cock in her mouth and started to suck and lick it and I soon came back to life. She sucked, licked and wanked it for a while till I spurted another load into her mouth, she opened her mouth to show me a mouthful of my cum and then preceded to swallow it all. 

We both got dressed in silence and as I was leaving I repeated that we shouldn't do it again. She said ok and I left. 

She later started dating someone. But it fizzled out quickly, whilst I really enjoyed the sex, and the wanks I had thinking about it, I knew I couldn't do it again. That was until I got a text from her....