Oops!

Walter's body begins to shimmer and shift unexpectedly, catching both Martin and Tim off guard. The transformation is sudden and dramatic, Walter's form expanding and changing right before their eyes. His body grows taller and more muscular, the feminine curves softening into hard, defined lines. The clothing that had been fitting snugly on the "girl" now bursts at the seams, unable to contain Walter's new, much larger frame.

Martin, still deeply embedded within Walter, feels the sudden change acutely. His eyes widen in surprise and a hint of discomfort as he realizes that Walter is no longer the petite and tight female teenager he had been moments ago. The room fills with the sound of fabric tearing as Walter's body continues to expand, his muscles rippling beneath newly formed skin.

"Oops," Walter says with a grin, looking down at his now-naked form. His voice has deepened, resonating with a masculine timbre that sends a shiver down Martin's spine. Walter flexes his arms, admiring his new physique with a satisfied smirk. "Guess I should have warned you guys."

Tim, still recovering from the intense experience, stares at his father in awe and shock. "Dad? What the hell?"

Walter chuckles, a low, throaty sound that echoes through the room. "Just a little side effect of the transformation, son. Didn't think it would happen mid-way, but here we are."

Martin, still inside Walter, shifts uncomfortably, trying to adjust to the sudden change in size and shape. "This is... different," he mutters, his voice strained.