My sister and her husband had planned to go on a 2nd honeymoon and asked if we’d let their 15-yo daughter stay with us for 2 weeks. We lived about 150 miles away from them but they dropped her off en-route to their destination. Cathy had always seemed to be a very conservative and well mannered girl. Things went as expected the first cpl of days with her dressing conservative. But things started to change on the third day. I’d taken the cover off of the pool and got it ready for the season. It was a nice sunny day and warm but not too hot. My wife Lynn asked Cathy if she wanted to sunbath with her and Cathy quickly agree but said she hadn’t brought a swimsuit. Lynn took her in the bedroom and was going to see if one of hers would be OK.
Lynn had opened the drawer just as the phone rang so she said she’d be right back. She was on the phone about five minutes and when she came back Cathy had opened another drawer and it was one of the drawers she kept her sexy lingerie in. Cathy was standing there holding one of my wife’s garter belts against her body and said she bet she’d look hot in that. Then commented how she bet her boyfriend would love to see her in that. Then she put it back in the drawer and picked out a totally see through night gown and held it up to her body looking at herself in the mirror. She looked over at Lynn and told her she could see why I always seemed so happy, but then really surprised her when she asked Lynn if she thought I’d like to see her in that and said she’d noticed how sometimes it looked like I was checking out her body.
Lynn just told her any guy would probably like to see her in that because she had a very nice body. At 15 she was already 5-10 with long sexy legs a firm slender body with nice 32 C tits. Blonde hair to her waist and beautiful blue eyes. They put the sexy outfits away and picked out a couple of bikinis to sunbath in. They’d only been out there a short while and Cathy looked around and said no one could see them and asked if she could take her top off. Lynn said sure and took hers off too. Lynn put some suntan lotion on and asked Cathy if she wanted some. Cathy said sure and asked if Lynn would put it on for her. Lynn started putting lotion on her back & shoulders when Cathy asked if she’d put some on her front. Lynn put lotion on her legs and stomach and went to hand the bottle to Cathy so she could put some on her boobs when Cathy surprised her saying be sure and put a lot on my boobs and rub it in good. Lynn was turned on by the 15 yo’s hot body but a little nervous with it being my sisters daughter but she did as asked and rubbed lots of lotion on Cathy’s firm young tits. Then got a real surprise when Cathy said she’d like to rub some lotion on Lynn.
Lynn stood up and Cathy started by rubbing it on her legs, her hands going up between her legs and even rubbing some under the bikini bottom her fingers rubbing against Lynn’s pussy. Then she put it on her ass that was totally exposed, as she did cupping her ass and commenting on what a nice ass Lynn had. She moved her way up my wife’s back and shoulders then had her turn as she put lotion on her stomach, again letting her hand slide into the bottom. Her hands moved up to Lynn’s big tits and cupped them lifting them up and said how much she liked her tits and how she’d wondered what they’d feel like. Then without warning leaned forward and took one of them in her mouth and started licking & sucking it, running her tongue around the hard nipple. She sucked on it for about two minutes then looked in Lynn’s eyes and said you won’t tell my mom about this will you? Lynn assured her she wouldn’t and Cathy went back to licking & sucking my wife’s tits for a few more minutes. Then she asked Lynn if she didn’t have so much suntan lotion on her boobs of Lynn would like to suck on her’s. Lynn was honest and said she’d love to suck on them. At that Cathy said why don’t we go in and wash all this lotion off and have some fun? Lynn quickly agreed still telling herself not to do this but not able to stop herself.
They took a shower together washing each others bodies and kissing & sucking each others tits, then moving to the bedroom. Lynn got turned on when Cathy said she’d really liked doing what they’d done outdoors knowing someone could have walked up on them and seen her sucking on Lynn’s tits. It turned out like Lynn my niece was also an exhabitionist. The explored each others bodies sucking each others tits and eating each others pussy. Lynn at 35 was really excited being with a girl 20 years younger than herself. As things were winding down Cathy asked what I’d have done if I’d have come home early and caught them in bed? Lynn told her I’d probably gotten mad. Then added mad that they had started without him. Lynn knew how hot I thought my niece was so asked her if it would turn her on for me to see them together, or maybe if I joined in. Cathy said she could tell by the way she’d seen me look at her that I’d like to fuck her. Then asked Lynn if she would be OK with that? Lynn quickly said she’d love to watch me fuck Cathy and maybe even the three of us hook up at the same time. Lynn was surprised when Cathy said she’d never been in a threesome with a guy & girl. So Lynn asked if she’d been with 2 guys?. But Cathy said no she’d been with 2 other girls at the same time a few times though.
When I got home they both seemed to be really up beat and excited about something but I didn’t say anything. We had a nice dinner and I went and took a shower. When I came out of the bathroom there was Lynn & Cathy laying back on the bed naked except both were wearing a garter belt & stockings. I was totally naked so they saw my cock spring to life. I didn’t ask any questions I just said so I guess it’s time for dessert. I was walking toward the bed but Lynn said not just yet and pointed to the chair in the corner. I went and sat where I’d sat and watched my wife fuck many other guys over the years and several girls. They started kissing and sucking each others tits and then move into a hot 69. After a while they looked over and asked if I was just going to watch or was I going to join them? It was like being in a dream looking down watching my sexy 15 yo niece sucking my cock as my wife sucked her tits. Then Lynn had Cathy straddle me and as her tight young cunt slid onto my long thick cock it was amazing. As she rode my cock she leaned forward so I could fondle & suck on those big teenage tits. I’d planned on pulling out but if just felt so good I just kept pounding my cock deep inside that sweet young pussy until I exploded inside her as she moaned and screamed in extacy as she had a massive orgasm just after I’d filled her pussy full of hot cum.
When I pulled out Cathy went straight to my cock and started sucking it again as Lynn went down on my niece’s cum filled pussy. We had sex almost every night until her parents picked her up. It was sometimes just the girls and a few times just Cathy and I. We of course had some more ffm threesomes, but at her request one night I invited a trusted friend over and she had her first mfm threesomes. We went out to a park one weekend where I took nude pics of both girls separate and together as well as some at home of Cathy in some of Lynn’s sexy outfits and of her sucking my cock. We hated to see her leave but we had some great memories. And after her visit I confided in Lynn that as a pre-teen I’d started having sex with my sister ( Cathy’s mother ). Now if only some day she has a daughter I could fuck in her teens.