When I went off the college, my parents both went through a sort-of mid-life crisis. I was the youngest of three kids so when they found themselves with an empty house, it invigorated them and they both found new activities to go along with their busy jobs. My sisters and I often commented on how they were both more fit and seemed happy all the time.
I'm 23 now, out of school and living out of state. Last summer, my parents paid for us kids to join them for a week at a resort near Lake Michigan. My sisters showed up with their boyfriends, and I brought my girlfriend, Carole, with me. We were all staying in a large cottage and fell into a relaxed schedule pretty quickly.
On the third day, I woke up late and found my mom reading a book with a cup of coffee. She was dressed in a nice t-shirt and a pair of sweat pants. My mother had gotten into exercising in the last few years so she was often in some sort of work out clothes. She is in her fifties and petite, but her skin shows her age. She has short hair with a mix of black and gray, small breasts and a healthy butt. I've often found her attractive, but never thought much more about her.
"Nice of you to get up," she said looking up from her book.
"Yeah, I guess I needed some sleep. Where are the guys?" I said as I found some coffee and a danish. I knew my girlfriend and my sisters were out on a marathon shopping trip in the city.
"Your father took the guys golfing first thing this morning and the girls are out shopping," she reported. "That leaves you and me."
"And what are you planning to do today?" I asked as I ate.
"Well, I'm thinking of a bike ride. Are you up for it?" She asked.
"I'm game, but I better have another Danish." I joked.
I put on some shorts and a shirt and met my mom out in the driveway. She was stretching her legs and she grabbed my attention when she bent over to touch her toes. Her shirt wasn't tucked in and it fell with gravity. I was walking up behind her and could see the sides of her small breasts in her lacy white bra. She kept stretching without thinking about the show she was giving me. I pretended to do some stretching with her and tried not to get caught looking at her. Her sweat pants were tight and I could see her panty line as she stretched. I was glad to be wearing some tight underwear to keep my cock from pitching a huge tent in my shorts.
We were on our way soon enough and enjoyed the tree-lined trail. I rode behind her and fought at times to keep up with her. Going up hills, she would stand up from the seat and I took in the view of her ass in her tight sweat pants. The top of her panties showed at her lower back where her shirt had ridden up. I could tell they were some silky purple material with a lacy band. I had enjoyed inspecting my mom's lingerie when I was a teenager and it was always pretty conservative – large white panties, no-nonsense bras, etc. The lacy purple part was new and it really got me going. I imagined how her cute ass looked in them as I followed the panty line around. I couldn't believe I was starting to lust after my mom.
As we rode, we talked about various things, my sisters, my job, my girlfriend, etc. I asked her how she and my dad were doing and she dropped a bomb very casually.
"Oh, your father and I have been doing well. Ever since we opened up our marriage, we really enjoy the time we spend together."
I rode up alongside her to find out more. "Opened up your marriage? You mean..."
She finished my thought, "that we have other sexual partners, yes. I thought your sisters would've told you by now."
I was shocked and turned on at the same time. I immediately pictured my mom on her back with her legs in the air, small tits jiggling, urging some random guy, "fuck me, fuck me, fuck me."
"No, they never told me." I responded trying to sound composed. "Well, good for you two."
"You know, we really do love each other, but sex with the same person for thirty-five years can get a little stale," she explained very matter-of-factly. "It's exciting to have fun with other people and then come back to your life partner. I only recommend it after thirty years or so. Our relationship wouldn't have lasted if we did it when we were younger."
I was just letting her speak as I drifted behind her a bit. I was letting it all sink in. They really have changed, I thought. As my mom was talking, the top of her panties were still visible and now even more of a turn on. On top of that, her back was sweating and her bra was becoming more visible as the t-shirt clung to her. I was now picturing her in just her bra and panties rubbing her ass on the bike seat.
The conversation changed and we rode for a while longer. We returned after about an hour and we both needed a shower. Since there was only one bathroom in the cottage, I let her go first.
She didn't close the door completely when she went in the bathroom and from where I was sitting, I could see in just a bit. She wasn't standing right in my view, unfortunately, but I did see her walk by wearing just her bra and panties. She was a hot little package and those purple panties looked so sexy on her butt.
When she was done with the shower, she came out wrapping in a towel that just barely reached her thighs. With her short hair wet, no makeup and bare skin, she looked old, but her legs were firm and her face was cute.
"All yours," she said with a smile, and I went in to shower.
Immediately I spotted her clothes piled on the floor with the purple panties on top. I picked them up and held them in front of me. I could smell her in them and the silkiness was totally turning me on.
