Jeff woke up early in the morning. Mary was peacefully sleeping next to him as his fascinated about the changes of his girlfriend. He was immediately turned on when he thought about how easy she overpowered him. Then, a strong desire formed in his mind. He also want to be stronger and overpower her. He shortly checked on his girlfriend and confirmed, that she still was sleeping.
Jeff sneaked out of the bedroom down to the living room and spotted the box of vials. Excited, he searched for anything to make him stronger and found two vials, one with a flexed biceps and one which showing a small human with an arrow pointing to a much larger human.
"This must some kind of muscle and height vials", guessed Jeff as he thought about how much he should drink.
Taking a gulp from both vials, Jeff's body immediately reacted to the liquids as every muscle in his body grew drastically and his head shoot up slowly towards the ceiling. Jeff felt dizzy as everything around him seemed to move away. His muscle continued to grow past his wildest dreams. He flexed his biceps and was shocked how muscular he got. Shortly, he imagined what would happen if he would drink more from the muscle grow vials. "I feel so strong", whispered he, "Now it time to put those babies into action". Jeff looked around the living room to find something to test his newfound strength and spotted the couch. Confident he walked to one edge, bowed down and placed one hand under the big couch. He was a bit surprised when he lifted the couch with ease. "This is insane. I'm a lot stronger than I look", thought he.
Mary slowly work up when she heard loud footsteps. As she opened her eyes, she was shocked by the almost 7 foot super muscular version of her boyfriend grinning malicious towards her. His penis was about 2 foot long and fully erected. "Ready for round two?", asked Jeff with a lustful grin in his face. Mary was still a bit sleepy and before she could react, Jeff pinned her down ready to enter her. Not fully known whats going on, Mary tried to free herself but eventhough she was really strong with her muscular tentacles and arms, she could not move Jeff with all her strength. She tried to wrap all her tentacles at one of Jeff's arms, and pulled up with all her might, but she was simply to weak.
"Who is the strong one now?", mocked Jeff, "I really need you!!!" Jeff inserted his over sized manhood into Mary's small pussy, going only halfway in. Mary felt both pain and enjoyment when he rammed his penis in and started to change to her more soft form. Jeff was able to move further and further inside, until his penis was fully inside her. Both now felt unbearable pleasure as he fucked her hard. Mary was lost in pleasure and released all of her tentacles now fully enjoying the morning sex as Jeff spun around and pushing Mary up and down his vertical penis. The small octopus girls was helpless sitting on the big penis, while all her tentacles handing loose down around the shaft. Harder and harder he pushed her down until both came.