I couldn't believe my luck. My bonnie Heather was a dirty bitch, she loved cock and just could not keep her hands out of my pants. We wanked each other and fucked 2-3 times a day. She was classy though, dressed to impress always and spoke with the classiest northern England accent - quite clipped really. But she had the hots for my mate Rob. She never told me but whenever he called at our house her behaviour round him changed. She became flirty and always talked a bit dirty. She lovered to mention anal sex whenever Rob was round. I thought it was harmless fun but would she fuck him given the chance ? Events overtook my planning on a hot sunny day. Rob had called round to drop off some books he had borrowed and was in tight shorts and tee-shirt. Heather was in a bikini as she had been sunbathing in the garden. Heather had a stunning body, great firm tits - not too big and slim hips with a pert bum. When Rob saw her his eyes nearly popped out of his head. Heather took the books from him and bent down next to him to put them in the cupboard. Her pert bum was in the air facing Rob and I could see the gusset of her bikini had slipped sideways and her pussy was on show. Did she know ? The effect on Rob was instantaneous and his cock grew hard, in his tight fitting shorts there was no hiding his bulge. Heather must of realised her pussy was exposed and reached round to cover up. This happened in a few short moments and her eyes looked at Rob, she flushed and saw his cock making a tent. Without a word she just turned, pulled down his cock and clamped her mouth onto his dick. She looked at me and the look of surprise on my face must of said it all. Heather took Robs cock out of her mouth and told me to stop gawping and to start licking her cunt. I had never had a threesome but it looked like that is what we were going to do. I moved behind Heather, unable to take my eyes off her sucking Robs cock and slipped a finger into her bikini bottoms. Her pussy was dripping wet, my cock was hard and I just had to fuck her. I pulled out my cock and edged her bikini bottoms aside and started to fuck her. She was cumming before I was on my second stroke. Within a couple of minutes Rob was pumping his cum into Heathers eager mouth and I was shooting my load into her pussy. Dirty bitch, she uncoupled, said thanks boys and walked out to the back garden to carry on sunbathing ! Rob and I looked at each other, our cocks out dribbling cum and just smiled. We tidied ourselves up and Rob said he needed to go. Heather shouted 'come again soon' the filthy bitch. We never went further, it was a one off, Rob moved away, but called round last week telling us he had moved back. When he came in the house, Heather gave him a hug and squeezed his arse. He couldn't stay but it looks like things might get interresting soon. I am bi-curious and wouldn't mind sucking Rob's cock, it looked nice not sure though. Might have to fight Heather for a chance !