Over the next few nights Casey helped Mark learn how to control his new found power. Once Mark fully harnessed the power they had sex together. Mark grew a 1 ½ ft long pole and Casey was able to ride it all night long.
They were able to keep that going for hours because they could both increase their stamina.

The next morning Mark woke up to get ready for work and he thought of an idea. He looked over at Casey who was still asleep beside him and he decided to shrink and go along Casey’s sexy body. He kneeled on the bed and began to become smaller. He watched as Casey became larger along with everything else in the room. When he got down to about an inch tall he went to where Casey’s feet lay. He crawled on Casey’s leg through he pyjama bottoms when he reached her crotch. Casey was wearing black panties and Mark crawled under them and licked Casey’s pussy. He then crawled out of her panties and up her torso to her tits. Casey’s boobs looked like mountains from Mark’s point of view and he began to climb once he reached the top of her left tit he sucked her nipple which fit the capacity of his tiny mouth.
While Mark was enjoying himself he felt something move and paused and then he was nearly knocked off of Casey’s left breast when he realized that Casey was now awake. Mark held on for dear life as Casey walked to the washroom to take a shower. Mark was able to grab Casey’s long hair to stop him from falling. He then climbed to the top of her head. Once Casey reached the bathroom she stripped down and went to the shower. Mark still managed to hide in her hair the whole time that Casey showered without her noticing.

Once Casey was finished she put on some clothes and Mark was able to get back down to her boobs. Mark rested between Casey’s tit and her bra. When Casey finished getting dressed she changed to her playboy model form. Mark felt himself getting pressed tighter against Casey’s bra as she made her boobs bigger and he watched as Casey rose a couple of inches higher.

Casey went out to the garage and noticed that Mark’s car was still there. She paused and knew that he wasn’t inside the house but just assumed that he went for a jog that morning. She then felt like something was on her breast but ignored it. Once Casey got to the first shoot of her day Mark had to again hide in her hair as Casey had to strip naked for the shoot. It went well especially for Mark who was able to hide without getting noticed again. Mark was amazed at all the hot women who worked there.

Casey now headed off to her second shoot at Victoria’s Secret. Casey walked to the car and Mark loved it because her huge tits jiggled when she walked. Once she entered the car she changed herself again. Mark watched as his wife began to become shorter but he couldn’t concentrate on that that much because Casey was growing new F sized tits and again he was becoming even more uncomfortable.

Then he felt as if he was being released when he realized that Casey was changing bras. Once Casey took it off Mark fell down to her panties where he ended up spending the rest of the day.

Casey arrived back at home that night and was surprised to find that Mark’s car was there but Mark was not. She didn’t realize yet but Mark was still in Casey’s panties and needed to think of a plan to get out. Casey sat down in front of the television and turned the new on. Mark was able to sneak out of Casey’s underwear and grabbed on to her pants. He repelled down her pants and was finally out.

Then he went to the front door grew back to normal size and opened the door. Casey saw him and asked were he had been. Mark said that he was over at the neighbours house for something.

They ate dinner together and went through their normal evening routine. When they went to bed Mark said to Casey,

“Would you want to swap bodies for a day, you know, I’ll be you and you’ll be me.”

Casey thought for a while puzzled why Mark would ask such a question but she finally agreed and in the morning they would help each other prepare for the upcoming day.

When they woke up that morning Mark transformed to Casey. He grew two massive breasts gave himself a vagina and was amazed at how it felt to be in the body of a woman.

Casey then became Mark giving, herself a penis, shrinking her boobs and adding some muscle to her frame. Casey helped Mark dress (mostly because he couldn’t get his bra on) then she gave him the directions and plans for his day. Mark did the same and they were both on their separate ways.

Mark first had to go to the playboy shoot were he turned into Casey’s playboy model form. He did many things there and enjoyed the feel of talking about himself in the presence of the other women models. Then he was off to the bra shoot. There he made some improvements to Casey’s form there. Instead of being 5’10” Mark went to 6’ but left his giant F sized boobs the same. He had the most fun there because there were so many big breasted models there who only compared their boobs to the other models. Mark was proud to say he had the biggest ones. The rest of Mark’s day went pretty much the same but the same couldn’t be said for Casey.

This was the first time in years that Casey had ever done any real work at work. Mark was an insurance broker and had a pretty boring day all in all. She now realized why Mark wanted to change bodies for the day.

When they arrived home Casey and Mark stayed in their current forms as each other and again had a regular night. Then they decided to have sex as each other. Mark grew his boobs to the size of water melons and Casey grew herself a foot long shaft. Mark was so used to being on top but Casey instantly grew herself big muscles to hold Mark down. When Casey entered Mark they both felt a rush like any other and both fell back in complete ecstasy.

When Mark woke up the next morning Casey was already gone, which was pretty typical because of the multiple jobs she had. Mark wanted to live another day as a woman but this time he could be his own woman. He grew to a staggering 6ft 6 and had FF sized boobs. He looked through Casey’s clothes and found 1 shirt and 1 bra that would be able to contain that amount of breast flesh and the hint of muscle that he gave himself. He decided to only go to Casey’s bikini modeling because if he went to all four Casey would definitely get suspicious.

Mark arrived just after Casey did. Casey was busy getting prepared when she felt a top on the shoulder and turned around to see too giant breasts in a bra that could barely contain them. Casey stared in astonishment at the woman standing before her 6 inches taller than herself with boobs the size of basketballs.

Mark said, “Sorry I’m new could you please help me find a bikini that could fit me.”

“There aren’t very many.” Casey snorted jealous that there was a woman taller and with bigger boobs than her.

Mark began to get all the attention during the shoot. There was no model there, not even Casey who could compare to the sheer height and bust of the newbie. Mark eventually showed to Casey that she was nice and eventually they both ended up naked in a back room. Casey grabbed handfuls of Marks breast as Mark lay on top grinding his body over Casey’s and playing with her tits. Casey took out a dildo and they managed to have some fun sharing it.

The day ended and Casey went home to find Mark cooking dinner as usual. She was thinking while he was cooking. She then realized the risk Mark’s powers gave him. He could be cheating on him at work. She would have to test this out.
The next morning Mark woke up and Casey was gone as usual. He didn’t have any erotic impulses today and decided to go back to work. He arrived with his usual double-double coffee and sat down to review the day ahead of him when he saw the most beautiful woman walk by him. Little did he know that that woman was actually Casey.

He looked and couldn’t help but stare as this woman was passing by. She was very tall with long legs. Mark put her at 6’5” an inch taller than himself. He couldn’t help but watch the EEE boobs on this woman bounce as she walked and the nice round ass shake with every stride.

Casey noticed the crazy stare that Mark gave her. She knew that she had him right where she wanted him. She turned around came to Mark and said, “Sorry I’m new could you tell me where the photocopier is.” Mark gladly led her down the hall to the copy room. When they both entered Casey slowly closed the door and locked it. She made Mark sit down and she leaned over him. Mark couldn’t help but stare down her shirt at Casey’s massive cleavage. Casey began to toy with him. She liked him and kissed him madly in the face then she undid her blouse and bra and showed her massive mams. Mark couldn’t help himself as he undid his pants and her skirt and the next thing he knew he was straddling Casey. Casey had put more muscle on herself than what appeared so she quickly flipped Mark over and was now on top. She stuffed her titanic tits in his face as she rested on his long pole.

After that adventurous day Mark went home and could only think about going to bed.