At first Adam seemed like an ideal guy to share an apartment with - mature, quiet and on top of his finances. Despite being some fifteen years older than you, he was incredibly down to earth and understanding of your youthful needs, if a little on the reserved side in comparison to your more outgoing personality. More than once he had tolerated you stumbling in blind drunk at late hours of night and had even left a glass of water by your bed to help you sober up a little before sleeping. All in all, he was a good guy.
Unfortunately for you, Adam’s kindness was merely a facade. The reason he had accepted your application to move in with him was because he saw something in you he liked - multiple things actually - and he had the means to take what he wanted. You were a helpless deer stepping right into his trap, playing into his hands without ever realizing what you were doing. You wouldn’t have been the only one to be in such a place, you were just unlucky enough to catch his eye and truly motivate him to do something about his desires.
The changes started slow - you felt a little more lethargic with every passing day and weren’t quite hitting your usual amount of reps during your workouts which was a pain but it wasn’t really all that concerning until your friends at the gym started to refer to you as skinny. Now that bugged you, not just because you had to hear the nickname repeatedly but because they were right! Your muscle mass seemed to be vanishing into thin air, leaving your limbs stick thin and your chest lacking any real definition.
Much to your dismay the stress of your sudden inexplicable muscle loss was getting to you so much that it was visible in your skin which seemed much more drawn and lacking its usual golden glow. Lines around your eyes and lips became more pronounced while your perfect complexion began sporting a number of blemishes and scars. Even looking in the mirror made you miserable and eventually you dropped your gym membership entirely, too humiliated to show your face in front of the guys you had one teased for being unable to match your personal bests.
Extending your time inside the apartment meant that you saw a lot more of Adam and he strangely didn’t seem quite himself either. Unlike you though, he had evolved into a more impressive specimen with clear skin and a youthfulness to his features. His shirts clung desperately around a muscular frame and his traps in particular were sharp ski slopes down to his broad shoulders. You were at a total loss for words when you first saw him without his shirt, two fine pectorals sitting above a perfect six-pack of abs. What had happened to the out-of-shape middle-aged man you had agreed to tenant with? It was easy to mistake him as even younger than you, especially given the wreck your body had become in recent weeks!
As your hair began to take on flecks of grey and his took on a fiery red shade, you slowly began to understand what was happening. Adam had been draining you of certain qualities ever since you had moved in - your youth and muscle in particular. In place of them he had given you his advanced years and damaged complexion, not to mention the scrawny frame that had made him seem so non-threatening at first.
With the reasons for your unwanted changes now present, you sought Adam out with the intention of confronting him and demanding your body back. As you attempted to make your demands though you found yourself at a total loss for words and realized in horror that the older man had not only drained you of your impressive physical qualities but also your confidence and arrogance, leaving you weak and submissive in his place. You stared open-mouthed at the hunk you were now lucky enough to share an apartment with, wondering how long it would be until Adam kicked you out of the place entirely and left you to languish away as a sad old man while he enjoyed your stolen youth!