Chapter 13
Diana entered the bathroom, locked the door, turned on the cold water on the shower and felt the water cooling down her body. What had just happened? Did she really just had an orgasm by seducing Timmy with her muscles? How was this possible? He was her brother, for crying out loud. It was wrong.
And yet, the idea of dominating someone like that, specially a man, an older man, was inebriating. Ever since she saw Becky by the pool, almost two years ago, she felt the need to be admired by her body. Her hard, muscular body. That's what she wanted when she started working out. From there to the whole idea of not only having sculpted muscles, but to put those muscles to test and being stronger than most people around, and to be pleased by that, was a quick trip to Diana. Now it seemed she had reached the epitome of what she truly lusted.
As her body cooled down, Diana had made up her mind. She couldn't do that to Timmy again. Not only it was wrong, but he was a good boy, and that could scar him for life. Maybe it already did.
The following weeks were hard on her. More than once she almost gave into her urges. Once, after a rather fierce upper body workout, feeling swollen and big, Diana walked down the corridor and almost broke into Timmy's room. She pictured herself entering the room grunting and flexing her whole body, watching him succumb to her power, beg for her mercy. But she stopped herself. It was wrong, and she couldn't do it.
As time went by, Diana kept growing. Being able to use the school gym was making wonders to her training. She was able to work different muscle groups, concentrate exercises, having workout partners that pushed her. And, of course, her competitive mind made her always wanting to get better and bigger. Having people around to compare with was the best fuel she could have. Diana, now at 15, was pretty sure she had reached her adulthood height, but she loved that every month the scale told her she had added a couple pounds. Now at 163, she knew she was about to enter a plateau on her gainings, but she felt happy with how big she was.
Even though she had promised herself not to put herself and Timmy on that spot again, sometimes her primal instincts took the best of her. Every once in a while, when Timmy was around, she provocatively flexed a muscle for him to watch. A bicep here, a chest there, she loved the attention her older brother could give to her body.
Mid term approached and with it, their school always held a themed beneficent party. This year's was Marvel x DC. Everyone was supposed to go in costumes. Timmy quickly decided he would go as Deadpool. Diana, on the other hand, was having trouble finding a character that fit her personality. Then she came up with an idea. Unfortunately, this would mean expose herself and Timmy to a very dangerous situation.
"Uh... Timmy, about tomorrow's party..."
"Yeah?"
"Listen, do you think you can help me with my costume? I might need some assistance on putting it together"
"Sure... what are you going with?"
"Oh, you'll se tomorrow"
The next day came, and around 7pm Timmy was all dressed up into his brand new Deadpool costume. He invested a few bucks on it, but it looked cool. The whole outfit, the two fake swords on the back... and he even did some make up to make his face scared if he decided to take off the mask at some point. He heard Diana calling from her bedroom and went there.
"So, what is this surprise costume you're..."
Timmy stopped talking. Diana had a Supergirl outfit on her. The elastic fabric was really tight on her body, the blue spandex with the S on the chest glued to her muscles. The red skirt stopped about 2 inches above her knees, letting her quad muscles contract freely. The weird part, however, is that the costume seemed to be torn apart on it's left shoulder, exposing Diana's chest, neck and left arm completely. Timmy could see she had a green bra underneath the costume. It showed under her left armpit, since it was a strapless one.
"Uh... what the hell are you trying to do?" Timmy was clearly confused by Diana's choice
"It's not ready yet, silly. You see, I couldn't decide if I wanted to go Marvel or DC. So I figured... both" Diana extended Timmy a big cup with some green ooze in it, and a brush. Timmy still hadn't figured it out, just stood there, looking confused
"I present you... Supergirl meets the Hulk"
Now he got it. The green stuff was body ink. Diana wanted Timmy to paint the exposed part of her body with it, so she would be half supergirl, half Hulk. He had to admit it, her idea was awesome. And both characters fitted her perfectly.
Diana sat down on her chair backwards, so the rest was in front of her. She pulled her hair into a tall ponytail so Timmy could begin with her back.
"Now listen, if you have to, paint the exposed parts of the bra too. I want it to be all the same color, ok?"
"Y-yes..."
Timmy removed the gloves of his costume, rolled up his sleeves and started. He gently used the brush, contouring every lump on Diana's back. This was taking too long. Diana had a lot of body surface exposed. Taking a deep breath, Timmy knew there was only one way he could make this faster. With his hands. Dropping two big chunks of ink over her back and neck, Timmy started spreading it with them. He noticed Diana's back muscles looked bigger from the time he caressed them. And this time, she wasn't even flexing.
Diana felt Timmy's touch with a bit of surprise. She knew this must have been hard for him. She tried not to think about it. As Timmy worked his way up from her lat to her shoulder, she heard his breath getting heavier and louder. It turned her on. She knew Timmy was aroused by her muscles. Diana fought the urge to flex them.
Timmy finished Diana's back, spending a good deed of time on her trap. It felt thick under his fingers. Part of him wanted her to flex them, so he could feel them in all their mighty.
"Alright, turn around"
Diana sat down, looking straight at Timmy, who very professionally started completing the circle around her armpit. Timmy, carefully trying to avoid any breast started moving to Diana's front. Once he reached her pec muscle, Diana flexed it on a reflex.
"Oh, sorry" She immediately apologized.
"Thats... that's ok. Do it again. It's... easier to... paint it"
"You sure?" Diana contracted her pec, holding it contracted. She felt Timmy's hand spreading the ink on it, almost as if he was feeling it's hardness.
"You... you got... bigger" he said in a low voice
Not sure of what she should say she thanked him
"oh... yeah... glad you noticed. You liked it?"
"Y-yeah..." Timmy was now on Diana's shoulder. It had a full cap, with a big vein on it. It wasn't there before. He felt his dick making his way up. And his spandex costume wouldn't hide an inch of it.
Diana sensed it right. Timmy was aroused. Even without trying, her body did all the work for her. It made her feel good. Feel powerful. Feel in charge of things.
"Let's.. let's do the arm now" Timmy whispered
Diana extended her arm to him. He started from her hands, feeling how smooth her skin was. How was this possible? Those hands grabbed, pulled and pushed large amounts of weight, and their touch was still gentle and soft. Timmy noticed that the vein he saw on her shoulder actually began it's course on the back of her hand, running through her forearm and bicep. There was a second one, that ran from the other side, contouring her bicep from behind. Hypnotized, he followed that trajectory as he spread the ink on her forearm.
Diana watched Timmy's eyes devour her muscles. Each second it got harder and harder for her not to simply flex her muscles and watch him beg. And his touch was gentle, but firm. It was the touch of someone who truly admired her muscles.
Timmy moved himself so Diana's arm was extended transversally in front of him. His face was aligned with her elbow, as he finished her forearm and moved up to her arm. He noticed how amazingly Diana's tricep filled her arm well, giving it most of it's volume. Instinctively, Timmy placed both his hands as if hugging her arm. He noticed how little was left of his finger before he could complete the circle around it. Maybe the tip of his index finger, no more than that. Diana's arm was thick.
That did it for Diana. Watching as Timmy was trying to measure her arm was too much for her. As soon as he touched his fingers, locking her arm inside it's circle, Diana flexed her elbow, causing her bicep to expand beautifully. They both watched as Timmy's hands were being pushed apart by the growth of Diana's mighty muscle. If relaxed there as a fingertip left, now there was a just as big gap between his hands. Diana's swollen muscle was a hard ball of concrete, peaked and prominent. She relaxed and flexed it again, even harder. Timmy just stood there, with both his hands over it.
"Big, right?"
"Yes... big" was all Timmy could say
"Go ahead... try to squeeze it"
Timmy pressed his thumb against the gorgeous ball of half green painted muscle. It didn't budge an inch. It was like pressing against steel.
"My God, Di... your muscles are the greatest think I've ever seen"
"Thank you, Timmy... now please, finish up the painting... then I'll give you a sample of She Hulk" Diana grinned
Timmy finished up Diana's arm. She stood up, looked herself in the mirror. It looked amazing. Her hard muscles did look like the Hulk's.
Timmy was dead silent watching his sister's body in green ink. She slowly turned around, facing him.
Grunting, Diana flexed her whole upper body. Even the side hidden by Supergirl's outfit looked big. But the paint covered naked side was... something else. Even Stan Lee himself could not have drawn such muscles with that perfection. Diana grunted again, causing her body to bloom some more
"So, brother, what do you think?"
"You look... wow" was all Timmy could say.
Diana walked towards him, and Timmy stepped back, until he hit the wall. Diana giggled. It was like Timmy was truly afraid of her mightiness.
Raising her both arms, she flexed her biceps once again
"Who knows, Timmy, next time I'll go full Hulk. What do you say?"
"It... it would be... amazing"
Still holding her flex, Diana realized things had already gone south today. So, why don't enjoy some more?
"Go ahead, Timmy. Feel them. I know you want"