"Well dad, I was kind of hoping this could maybe...make us closer? I've felt a bit distant from you lately."
Mike smiled and slapped his son on the back, before pulling him close.
"Aw, don't worry Jeff, you'll always be my Mike Junior."
After he said that, he paused, then smiled slowly.
"Hmm, that gives me an idea. I know a way we can be very close."
Mike told Jeff not to look while he set the changes, leaving it a surprise. He said they would try it for a week, and if Jeff didn't like it then they could always change back early. Jeff heard busy clattering on the keyboard, before finally it was set.
Mike pressed confirm, sealing their fate into whatever change would happen for an entire week. Jeff smiled, blushing, as his dad hugged him tightly from behind
Suddenly, Mike grunted in discomfort, bending forward slightly. He began breathing heavily and shuddering, grasping his crotch as he moaned in pain. Jeff went pale.
"Dad? What's wrong?"
Mike fumbled at his pants, wincing, and unbuttoned them, pulling them down. Beneath, the older man's boxers were shuddering. The proud and generous lump in the front began to deflate, the cotton slowly flattening. Mike pulled at the waistband, sliding it down to watch the change. Jeff blushed as he saw his dad's hairy crotch, but stared in awe as the thick, powerful cock pulled inward, shrinking and vanishing. His hairy balls tightened and pulled upward, disappearing into his flesh until finally, nothing remained between his father's legs but a smooth, unbroken patch of pubic hair.
Mike looked down, slowly stroking his hand across the smooth patch of skin, then looked up at Jeff with a smile. Reaching forward, he wrapped his arms around Jeff and gently kissed him on the forehead. Jeff shivered, blushing and feeling incredibly hot. His skin tingled where his father's body touched against it, and made him pant.
Mike laughed quietly, his eyes closed and breathing in slowly.
"You're starting to smell different, son."
Jeff blinked in confusion, and slowly lifted his arm. With curiosity, he sniffed his armpit, and was surprised at the unfamiliar scent that met his nose. Where once was the familiar lifelong smell of his own sweat, instead was a new, humid and potent musk. It smelled mature, and masculine, and so filled with manliness that it made Jeff shudder with sudden arousal.
However, that arousal manifested itself in a strange way. Jeff felt himself blushing, his face turning red as he felt blood flowing to his head. He began to pant, and feel hot.
"Daff? What'ff happenin?"
Jeff struggled to speak. His tongue felt swollen and hard. He began to drool a little, and it tasted oddly salty and sticky. He shivered more as his tongue began to reshape, rolling into a cylinder of flesh as it hardened and lengthened. He was forced to open his mouth as his tongue began to poke out from his mouth.
There was a slight pause as Jeff stood there, drooling and hot, until his dad finally began laughing. Taking hold of his shoulders, he moved him to the full length mirror, and hugged him from behind as Jeff witnessed his change.
Where the teen's tongue had once been, now protruded a thick, erect cock. Not only that, the fleshy rod was oozing pre and was quite familiar, as he had seen it only moments before; it was his father's.
Mike grinned mischievously, wrapping his arms around Jeff's chest and squeezing him close. Mike blushed and shivered at the contact, feeling his old man's heart pumping in his chest behind him, beating in perfect time with his own, as if they shared one heartbeat. The skin of his dad's hand felt like a part of him where it touched him, and closing his eyes he found he was able to sense Mike's presence as if his body was a part of his own.
Or more accurately, as if Jeff was a part of his dad.
"There, son. Or I suppose for the next week I shouldn't really call you that, since you're not really my son at the moment. You're my Mike Junior...literally. My walking, talking, living cock."