But I've only just discovered that my sister-in-law and her boyfriend actually like being watched. I'd schemed and planned for months about how I might get to see them fucking each other, then on Monday of last week when my wife was at work and I was left alone with the two of them, I got to know their secret - and they got to know mine. I kept glancing into the living room from the kitchen and could see his hand riding up her skirt, but it wasn't till I caught her eye that I realised she didn't mind me looking. Instead of shutting the door or taking him to her bedroom, she just looked me in the eye and got hornier with him - kissing his neck and rubbing his cock through his pants. My wife likes sex, so I don't know why it should have been such a surprise that her sister Anna was liberated as well. They knew I was watching as he lifted her t-shirt and pulled down her pants and knickers. It was excitement like I hadn't experienced before, and now I'm hooked.....