As you grabbed the food from the fridge the reality of the control you wielded crystalized into clarity. You aren't worried about Keith taking over the world, but there was nothing stopping you from doing so...
Within the hour you pondered that you could easily have over 100 slaves just like Keith. The limiting factor was the keys, but it would be an upgrade to give them the power of the keys which could be used at only your command... You zapped him with the keys enough times, he probably already could... Then you could activate the android persona, take a nap and wake up to thousands of slaves. Within days you could remove much of the collective will from the state, cowing them to your whims and shortly thereafter, the nation, then the world.
Exciting? Yes. Horrifying? Yes. Something you want? No? No. Definitely... Most likely not!
The excitement you felt earlier was replaced by a weight, you've stolen the humanity and free will of your friend and roommate and the only thing stopping you from returning it was that you like the power he gives you. Are you a bad person? Are you the villain? For Pete's sake you can't even bring yourself to tell him the real reason why you can't turn him back.
Keith returned from his shower wearing a t-shirt and basketball shorts, oddly more muscular and with a grin that told you he noticed and was enjoying it. "Hey, I'm not sure what happened but its like my skin absorbed the water for future repurposing... not sure why I had to piss out all the beer from earlier. Beer to muscle would be a good trick, make every dude on the planet jealous in one go..." he let out a lighthearted chuckle sitting in one of the newly upgraded recliners...
"That's why..." you muttered, finally realizing the truth.
"What?" Keith leaned forward.
"That's why you can never be human again." you said with a biting tone that was in all actuality directed at yourself.
"Wha..."
Your eyes shot up and hit him with with such intensity he leaned back, "I command you to turn into a buff cowboy version of a 24 year old Keanu Reeves, complete with outfit, speaking style, and accent."
Keith was stunned but the android part of him immediately got to work, bulking him up, changing his hair and facial hair style, color and thickness. Within a few seconds cowboy Keanu was staring back in confusion... "Oh I misspoke," you spat bitterly, "I meant I want you to look more like a tan, Brazilian porn star, ready to star on Baywatch who only speaks Spanish." Again his form and features molded into your desires, outfit replaced by a thong. Normally, you would feel attracted to this but you were making a point...
"AY! Amigo! Estas bien? Me estas preocupando!"
"Silly me, I meant Chris Hemsworth with pecks like the hulk but with boobs, lips, and legs like Jessica Rabbit, and I want you to be wearing the finest Armani silk suit." Keith ran to the bathroom tripping more than once as his balance altered considerably from step to step.
"What are you doing?" He bellowed sounding like Thor chiding Loki throughout countless movies, returning to the living room a moment later.
"The keys make things better!" you nearly screamed fighting back tears and mashing the unlock button at him.
"Okay?" Keith said not understanding.
"The only reason you can't be human again is because I think you're better this way! I tried to make my plant healthy and now it can put on light shows." You gestured at the plant shaped crystalline art that used to be your struggling indoor plant. "I'd rather have a slave than a friend and I'm the worst person ever!"
Keith's confusion flashed to recognition as he began to understand that this was about processing his guilt, loss, and identity rather than some action Keith took. "Think wifi and hit me with the keys again." Keith said calmly.
You complied, hot tears beginning to stream down your face. Keith smirked, "Think... I don't know Bio-fabrication facility and hit me with the keys again." Again, you complied beginning to tremble.
"Hey look. Can we maybe have this conversation in my normal body?" Keith asked.
You nodded and let out a light chuckle despite the torrent of emotions you were feeling.
Chris Hemsworth with boobs and long legs quickly reverted to normal old Keith as he took the few remaining steps to embrace you, "Hey, I'm still here... I could have just been turned into a router... or some star track level food recombinator thingy, but I didn't. You know what that means?"
You shook your head.
"That means that I'm worth more to you than free food for life or free wi-fi." Keith gave you a light shake.
"Give me the keys, let me show you something." He took the keys before you realized what just happened, he pointed them at himself and clicked unlock.
A second later Keith smiled... "I'm pretty sure I now have satellite radio, internet, and built in GPS." he said handing the keys back. "The fact that you can't turn me back into a human isn't your fault, I'm fucking amazing! I didn't ask you to be my Sir because I wanted you to be responsible for what happened to me, or to feel that you needed to save me from this fate, I don't need saving. I wanted you to be my Sir to hold me accountable... I trust you, and we both saw that leaving me in complete control causes mayhem... This afternoon was Keith serving Keith. I was working toward my own goals, in my own way... and I dare say I'm not so good at that. Never have been... and THAT'S where you come in. This isn't a curse to me... its the perfect excuse to let someone else worry about what should happen, why, how, when, and where."
You nuzzled into Keith's chest comforted by his words, feeling better you nodded and looked up ready to admit that you were being silly, but he continued, "You really don't understand..." Keith himself was now getting choked up, "You've been beating yourself up for being my destroyer, but in actuality, you're my savior. I never felt like I had a drive or purpose till now and every time I imagined my future it was always meant to be squandered in some office slowly turning gray, maybe bald... and definitely fat. But now my purpose is to sustain another person, one I have always cared about, and loved. You're my best man, man."
He was crying, you were crying, you did the only thing you could think of, you kissed him. When the kiss finally broke you did the only thing you could think of to break the tension. "So, does this mean your going to be a backseat driver for the rest of existence?"
Keith looked at you in disbelief and said, "In three hundred feet, turn left at the stop sign... then you have reached your destination!"
You both laughed heartily, "Shut up and eat your food, it's getting cold."
"I'm pretty sure I could survive off cardboard and vegetable oil now." Keith mused.
"More beer for me then!" you countered pulling his beer towards you
"WHAT?! No! That's only what I could live off of, not what I want to live off of"
"You said you didn't need it!"