While Rebbeca fucks your new endowment you reach for the formula and try not to think about the great feeling of sex with a bigger dick.
"Almost..." you think, "just a bit more.... GOT It!"
Without thinking you quickly swallow over twice the amount that Rebecca drank before realizing how awful it was.
"Damn that is NASTY!" you cough/sputter.
"What have you done?!?! Oh no...." says Rebecca who just realizes what's going on.
The look of horro in her eyes brings comfort to you as you begin going though changes...