Chapter 15

"Are you crazy?" I ask. "Mom's going to be out here in a minute. We have to stop and get our suits back on." I can't believe she wants to keep fucking with Mom coming out. "Just a few more minutes, Collins," she says, panting. "It'll take Mom a while to get changed. I'm so close. It won't take long."

She is watching the door, bouncing on my cock and grinding her clit against me. Just as she starts to cum, I hear the sliding glass door open. She pushes down hard, clamping her hot, quivering pussy around my cock. As Mom is stepping through the sliding glass door, Lilly quickly jumps off my cock and swims away from me. We both struggle to get our swimsuits back on, before Mom gets to the pool.

Lilly is smiling at me and treading water in the deep end of the pool. Her Mom is walking down the steps, in the shallow end, near me. Mom keeps herself in shape and looks about ten years younger than her 37 years. She's wearing a light pink two-piece swimsuit that shows off her tan, well-toned body. As I watch her get in the pool, it's easy to see where Lilly gets her sexy shape. Mom's flat stomach, the curves of her ass and her shapely legs all remind me of Lilly. Her breasts are much larger and a lot more of her tits are visible before they disappear behind the small triangles of her swimsuit top.

This suit must be smaller than her others because there is a thin white strip of skin between her swimsuit top and where her tan begins. Her swimsuit bottom is just a small V shaped piece of material covering her pussy with strings tied on the sides that connect to the material covering her firm, round ass. I'm not sure why I'm suddenly noticing all this about our mom. Maybe it's because my step-sister has gotten herself off and left me with a raging hard-on.

Mom reaches the bottom of the steps and plunges into the cool water up to her neck. She shivers and jumps back up to a standing position, yelling that it's cold. I watch her ample tits bounce up and down and can see the effect the cool water is having on her nipples. Her erect nipples appear to be embossed on her swimsuit top, as she stands there in waist deep water. 

She sees me staring at her tits and casually turns away, slipping back into the water up to her shoulders. She turns back and I notice her checking out the bulge in my swimsuit, before starting to swim to the deep end. It looks like she's smiling as she swims away. Could it be? Is my Mom pleased that I'm sporting a hard-on, while checking out her tits. This could be interesting.

"Let's play monkey in the middle, "I yell at Lilly and Mom.

My step-sister swims over to me, and whispers in my ear. "As long as it's your monkey in my middle." She laughs, and then more loudly she says, "Okay, but Mom's in the middle!"

It's a keep-away game with one person in the middle and the other two throwing a ball back and forth. Mom's in the middle and keeps jumping for the ball as Lilly and I keep throwing it around her and over her head. We're laughing and playing and dunking each other like a bunch of kids. Except, I can't keep my eyes off my Mom's tits with her thick, protruding nipple, pushing out the swimsuit material. I have a clear view of them, bouncing hypnotically, while she's jumping up to block the ball. When she's facing Lilly I just stare at the curves of her bikini-covered ass.

My cock has stayed hard the whole time and I catch Mom subtly eyeing it. Mom's getting more aggressive in trying to get the ball and I make sure there is a lot of skin contact, as we dive and wrestle for it. At one point, with Mom facing Lilly, I reach my hands around her waist and lift her up, pulling her back in the water on top of me. She's laughing as we fall backwards, and I manage to push my hard cock against her ass, as we tumble through the water. My hands slip up and "accidentally" brush against her tits as we both come up sputtering.

"You're cheating, Collins," she says, still laughing. "I'm not playing if you're going to cheat." She starts walking toward the steps. "Actually, I've had enough rough housing for one day. You guys are a lot younger than I am." She sits on the steps and I swim over to Lilly.

"I'll race you to the other end!" I say, winking at her. She immediately dives under water and starts swimming. We come up at the other end of the pool at about the same time and I take the opportunity to ask Lilly if she's noticed Mom acting funny.

"I've only noticed you acting funny, staring at Mom and constantly trying to touch her. What are you doing, Collins?" she whispers. "You aren't thinking of expanding your incestuous conquests are you?" she asks, smiling.

"Don't be silly," I answer, looking back at Mom sitting on the steps, leaning back with her eyes closed. Then I explain to Lily about how Mom reacted to me staring at her tits and how I'm pretty sure she was smiling and looking at my bulge. "Did you notice how hard her nipples have been all day and how she keeps looking at my cock?"

"Well, dad's been gone over two months, Collins. How would you like to go two months without fucking? I know I wouldn't like it." As she's saying this, she reaches down and starts stroking my cock through my swimsuit. "You are one horny guy, Collins. Is that because of Mom's nipples?"

"No! It's because somebody had to get fucked in the pool and then she swam away before somebody else got to shoot his load. But now that you mention it, I've stayed hard all day staring at Mom's sexy body, watching her tits bounce and seeing the outline of her hard nipples through her swimsuit. God, am I a pervert?”