This really happened to me on saturday aft, I still can't believe it now but have got to share the story. My wife was out shopping and I had just had a shower, I now she'd be gone for ages so decided to stick a porno on for 20 minutes or so and have a good w*nk. I was just getting into my rhythm when there was a knock at the door. Very frustrated I flicked the tv channel over and went and opened the door (wearing only a towel and a semi hard-on)As I opened the door my wifes sister Cheryl barged her way in and in her usual care-free manner said" get the kettle on andy, where's Jules?" "in town" I replied, "and I was in the shower" unaware of what she'd interupted she disappeared into the living room and I made a couple of teas. I took her drink through to her only to find her sat reading the porno dvd cover, embarrassed I snatched it off her and she laughed "shower eh? you dirty devil" I shuffled uncomfortably not really knowing what to say, she's a good 10 years younger then me and although quite chubby she is really cute. Then suddenly it got surreal, she rubbed her hand over my bulge in the towel and said "well you better finish off what you started andy, just pretend I'm not here" then she pulled the towel off altogether to reveal my semi hard cock rapidly hardening up again "wwwhat?" I stammered."let me watch you finish off and we'll say no more about it" she said, rubbing her hand down the length of my hard-on, totally shocked, but secretly very turned on, I flicked the dvd back on ans sat down beside Cheryl, the woman on the dvd had great tits and she was sucking like mad on some guys big dick, I gently rubbed my own cock at the same pace as she was sucking, then I felt Cheryls hand move mine away " let me help" she said, sat there naked been tossed off by my sister in law and watching porn - how the hell did this happen. After about 5 minutes I began to feel like I was going to shoot my load so I grabbed hold of the towel to catch my spunk "no need for that" cheryl said, "stand up quick" I did as I was told and she positioned my cock right up to her mouth but not quite in it, I couldn't take any more - I shot my load onto her face as she wanked me faster and faster, then with my cum dripping off her face she took my cock into her mouth and licked me clean.I just stood there in heaven as she licked and sucked til all traces of my spunk were gone, then she let go and disappeared into the kitchen. Afew minutes later I was back in my towel when she came back into the room, all cleaned up, kissed me gently on the cheek and said " i'll catch Jules later on, seeya hun" and disappeared out of the door, I just sat there, drained but giddy, it felt like a dream - it still does but wow was it a turn on. Don't know how I 'll react next time she calls but if I'm alone again I hope it happens again, I know its wrong but I 've wanked furiously as I thought about it last night and I'm very turned on just thinking about it.