You and your wife both started traveling a lot more this year for work so you two are constantly out of the house and needing someone to watch things for you. Your sister in law volunteered to actually move in for the time being because she has the free time to be a house sitter. At first you thought it was a good excuse to see your wife's sister in her sleepwear but you didn’t actually think you would risk everything to fuck her. This particular trip you told your wife it was a longer stay and that you wouldn’t be home before her, but you wanted to surprise your sexy house sitter and see if all her teasing is for real. It could not have turned out better, you actually caught her by the window, on the floor, pleasuring herself … she looked surprised, but then gets the hint as to why you're there, and says she has already seen your cock…she had been spying already! Now she wanted it up close and personal. Plus, she was reading that porn novel when you came in and interrupted , she looks so desperately horny, you couldn't leave her like that without giving her what she wanted. She was practically begging for it, she tells you she is going to make you hard and gag all over you. When she took your cock her hands, she almost melted with happiness, sucking and nibbling on the head at first, getting even more turned on by the feel and smells. Then she started shoving you in her mouth like she couldn't get enough, the sounds are incredible and you try hard not to cum too quickly.. But then she asked to call you daddy because she knows your wife won't do it and it sent you into a frenzy… she tells you to cum in her mouth and throat and says how she wont tell her sister, that it's our secret.