Its 11pm and it was a hot steamy night. And I needed to work up a sweat and burn off some frustrations from my impending divorce, so I decided to go to new 24hr gym for a workout. I hop on the stationary bike and start pedalling and listening to my music and getting into my groove. As I'm about 4 miles into my bike ride, a beautiful brunette wearing gray yoga pants and a pink tube tank top a little smaller than she should actually be wearing, started doing stretches just a little off center in front of me. I found this odd but, didn't complain. Her back to me she stands tall and stretches high to the ceiling and slowly bends down and touches the floor with her palms, without bending at her knees. She peeks up into the mirror and catches me staring at her. She gives me a cute smile and a wink. I smile back and try to turn my focus to the television in front of me. I can't. I'm drawn to her beauty and can't take my eyes off of her. She could sense my eyes on her and she turned to me. "Busted", I'm thinking in my head. "What the Fuck?". But, she smiles and starts walking towards me. I slow my pedalling as she approaches me and she said "Hi, I'm Sandi". I responded, "Nice to meet you. My name is Scott". I'm sorry for staring but, you are hot as hell and couldn't help myself". She giggled and asked if I'd like to help her do some stretches. I obliged and she took my hand and led me to a far corner. She grabbed an exercise ball and propped it against the wall and told me to sit on the ball. I sit down and lean back against the wall and she straddles my lap. I'm a little taken back by this and ask her what type of stretches she needed help with. She leans forward and whispers in my ear, "I want you to stretch my pussy", and bites my earlobe. I instantly start to feel the bulge in my shorts increased in size. "Mmmm. Someone's happy." She coos, and plants a deep kiss on my lips while sliding her hand down my torso to my stiffening cock. I open my eyes and notice in the far mirror that the the 2 girls at the reception area can see us and are enjoying the show. I start to panic and thing that this may not be a good idea but, my animal instinct is too much to harness and decide to let it ride. I lift up the front of her top and her tits spring free. Firm and perfect with rosy pink nipples. I squeeze her breasts and she gasps and bites down on my lip. Her hand slides into my shorts and she releases my swollen cock from my underwear and begins to stroke it slowly and tells me that she's going to suck my dick. She gets of my lap and gets on her knees while I pull down my shorts . She starts to suck the first couple inches, swirling her tongue around my head and making soft moaning sounds.. It felt amazing. I grabbed the back of her head and pushed her down as far as she could go. I look up and I see the gym staff watching and videoing with a cell phone. Being watched seemed to add to the excitement. She looked up and says that she wanted to ride my cock. She stands and tears the crotch of her yoga pants exposing a freshly shaved pussy. She grabbed my cock and guided the tip into her wet pussy. She was dripping wet and eased herself onto the entire length. She started to grind on me, leaned her head on my shoulder and started to moan quietly but with a wild intensity. I whispered in her ear, "We're being watched. "I know. Isn't it hot"? she replied. I agreed and she began to bounce and grind away at an increased pace. The exercise ball added to the experience seemingly to increase penetration on the bounce. She wraps her arms around tighter and grinds harder. Her breathing increases and her hot breath on my neck is to much to handle. I feel my balls begin to tense and she digs her claws into my back and bites town on my shoulder. The pain and pleasure of the bite is so intense that it sent shockwaves through my body. She groans out that she's cumming and begs me to fill her with my load. "I want you to cum inside me. Fill me with your cum." She whispers. I can't hold of any longer and my cock begins to spasm and I pump her pussy full with cum. She continues to ride me until I finish cumming. I open my eyes and notice that the ones that were watching from far away are now standing just feet away from us starting to put on a show for us. I think I'm going to like this new workout regimen.