Test Subject Sarah [Patreon Exclusive] (Patreon)

You didn’t expect for the hormones to have this strong of an effect.. all you did was sneak a single chew tablet into her breakfast smoothie; Sarah was only supposed to put on, maybe- 15 lbs? While you two sat drinking your morning coffee, you would have joined her in watching the morning news except for being preoccupied slowly watching her the crumpled folds of her baggy pajama pants slowly shrink over expanding thighs. 

She easily put on 15 lbs before lunch, somehow without noticing. It’s all you could think of, though. She sat a couple inches higher than normal in her chair at the table, and by the time you two had finished eating, she was even higher. Her once-baggy pajamas that she wore on weekends were now taut across two basketballs of new buttocks. 

By the end of dinner, her poor pajamas were practically thread-bare, well beyond what you would consider a safe maximum capacity. You thought nothing of when she excused herself from the couch, you were mesmerized by how high each independent globe travelled up and down as she climbed the stairs, with how far the two cartoonisly pert beachballs of fat defied gravity. 

Only when she called you to the bedroom a few minutes later did the full weight of the situation dawn on you. There she was, naked from the bottom down- demanding an explanation as to how she had doubled her bodyweight since this morning (She had only noticed something was amiss after stepping on the scale!) - and more importantly- why it was all localized to her behind. 

After you deliver some fumbled stutterings of a half-hearted explanation- (quite like a child caught in the cookie jar), she sighs- amusingly disappointed more than anything- and explains how she would have voluntarily participated in your mad experiment if you had asked in the first place; and furthermore- that you now need to make it up to her. Before you need ask how, she takes your hand, and pulls you onto the bed..