And in that moment, everything changed. That was a groundbreaking, trailblazing second in our lives. With only a handful of words, Mary and I changed our relationship forever. She was telling me, plain and simple, why she proposed that we worked out together. Why it didn't bother her that I wasn't really committed to my muscle development. Why she eventually flexed her ever growing muscles. It was all because that was exactly what she sought. Admiration. More than admiration, veneration. And I made clear to her why I didn't bother watching the strength and muscle gap between me and her increase by the day. Why I didn't mind taking time out of my life to watch and to help her grow. Why I actually pushed my younger sister to get stronger and more muscular than me. It was all crystal clear between us now.
As my hands ran from her fully pumped biceps, to her capped delta and finally into her prominent traps, I began kneeling down. At the same time, Mary turned around. My trembling hands touched the hardness of her abs muscles, the deepness of her crevices. Gently, but dominantly Mary grabbed the back of my hair and forced me to look into her eyes. They told me 'it's okay'. I told her the same way 'I know'
Mary's voice seemed to be coming from away, but was very decisive
"Kiss" was the single verb, the single command she gave me. She let go of my hair. My wet lips approached her abs, and Mary flexed them for me. As they touched, a flow of electricity ran through us. My tongue ran through every detail of Mary's wall of core muscle, taking it's time. I could smell her juices coming from below. I could taste her sweat. My hands instinctively grabbed her thighs, so thick and hard they could barely be noticed. As my fingers started to climb up, towards Mary's massive iron butt muscles, they touched the inner part of her thighs. I felt the wetness coming from there.
Mary moaned.
She pushed my head back, bending me a little backwards, and stepped forward, placing my head between her thighs. The smell was intoxicating. Even though she had her shorts on, I had no doubt of what to do next. I started kissing her, giving small bites, trying to use my tongue to stimulate her. She responded. Her thighs started contracting involuntarily. She moaned harder.
I was running out of air, but it was ok. I still could breathe. Although she could, Mary wasn't trying to hurt me. She was enjoying just as much as I was. I looked up and saw her, with her eyes opened, staring at herself through the mirror. Mary was holding a double bicep pose. She was admiring herself, and what her muscles had provided her.
I felt the pre cum on my shorts. Mary lowered both her hands and grabbed the back of my neck, shoving me into her. She now was screaming in pleasure. So was I, although I was completely muffed by her trunks.
Finally, she gave in. I felt her knees weakening and she let her body go, effectively kneeling in front of me. I came as she rubbed her body on my cock on the way down.
We looked at each other. And smiled.
"That was..."
"Yeah, it was"
Nothing else needed to be said.
As she regained her breath, still on her knees, she ordered
"Now leave. I need some rest"
"Yes, sister" I told her. As I made mention to get up and leave, Mary grabbed me by my t-shirt and pulled my head into her chest, flexing in and using her both arms to keep me in place.
"What did you call me?" This time she wasn't giving me room to breathe. It was clear that I had done something wrong and was being punished by it
"mmmm.... tress" My voice was becoming unintelligible. I was running out of air.
"I can't hear you" she said
I was getting desperate now. I placed my hands on her biceps and tried to push myself away, but it was useless. Mary was way too strong. I wasn't leaving unless she let me
"mmmmm sss.... ease!"
Mary giggled and relaxed the hold. I started breathing hard
"What did you say to me?" she asked again
"Y-yes... I'm... I'm sorry... Mistress" I told her. That had to be the correct answer, or I'd be going out in a few seconds if she crushed me again. I was fully erect, despite the fear. The idea that Mary could dominate me so easily as she did was the most arousing feeling I've ever had. She noticed it too
Mary was smiling. She got up and stared me down.
"Good... that's what I wanted to hear. You see, brother, from now on, when it's just the two of us, that's how you'll refer to me"
She raised her arms and flexed her biceps again. They bursted into life, bigger than ever
"That is, of course, if you want to see these again, to feel them again. Do you?"
"Y-yes, Mistress" I told her, in all my honesty
"Good... and, if you are good, perhaps I can let you feel their strength, just like now. I'd say you'd like that too, right?"
"Mistress is always right"
I could tell Mary was as happy as ever with our situation.
"Excellent. Now, I have a few ground rules to establish here, Jake. First of all, as I told you, I won't do any of this, or bully you in any way when there's someone else other than us. I will, however, because I can, make sure you understand how stronger I am when compared to you, how much bigger my muscles are, and how much damage they can do" Mary held my hands in between hers, as if we were making a pact "Is that clear?"
"Yes"
"Yes, what?" she started crushing my fingers together, causing pain I never thought could be so excruciating with such ease
"Yes Mistress" I screamed
"Good" she continued "Now, we will also work together, and that includes using part of our allowances say, to buy protein supplements, to find ways to make me bigger and stronger. I know we'd both like that. In exchange for your time, money and help, I'll let you massage me, oil me, admire and worship my muscles, and tell me how big and strong I am. I will, also for you pleasure, sometimes make sure you feel my strength on your, against your body. Consider it a double gift. It will pleasure you, as we both know, but it will also be a constant reminder of what I can do to you if you displeases me. Are we in agreement?"
"Yes, Mistress"
"Good. Now leave. But before you do, kiss" again she commanded, this time flexing her quads
I kissed both of them. Hard as oak. "Mistress has the hardest, biggest thighs I've ever seen"
She smiled "Aren't you a pleaser. Go"
"Yes, Mistress."
Later that day the three of us, me, Mary and dad had dinner together. If anyone looked at us they'd say we were a regular family. The laughter, discussions about the day, the chores after dinner, it was all regular. No one could tell that had been the most unique day of our lives, at least for two of the three members on that dinner table.
"So, kids, after we finish here, I'm off to shower and bed, ok? Clean everything up, and you're free to stay up and watch some movie or play videogames if you want" Dad told us
"We got it, dad. Maybe we'll pick a movie indeed" I answered him
"Yeah, don't worry, father" Mary added
at that second my cell beeped. I looked at it and it was a text from Mary. She must have typed it while we were chatting, just waiting for the right moment to send it. It said 'Meet me at the basement at midnight'
I shivered with excitement
