*This chapter was written by NotOnTime (myself)*

You think about it for a while and decide your plan of action. If you shrink yourself down first maybe you can catch her off guard and she'll listen to what you have to say. Maybe if she sees her son shrunk tiny and in trouble her motherly instincts will kick in to protect you. Either that, or she'll seriously punish you. You tried not to think about that outcome. There's a lot that could go wrong, but you decide to roll the dice on when she's in a good mood. Which happens to be right now when she's doing her yoga.

You sneak up to her bedroom door and open it slightly ajar. Looking inside you see she doesn't notice you, luckily she's facing the other way. What is facing you however is your mother's massive yoga pants-clad ass. She was bending over with her knees on the mat and her sizable rear resting on her feet. Continuing with her exercise she raised her big butt up high while keeping her hands on the ground. Her back arched and she thrust her wide tush outwards, making it jiggle slightly. Her massive butt cheeks began to spread apart in this pose, the thin fabric of her yoga pants rode up in the space between. The black material hugged and accentuated her curves nicely as they sunk deep into her crack.

You looked away from your mom's ass once you realized you were staring at it. You blushed, feeling a bit embarrassed. Your friends often teased you about her ass, and as much as you hated it, it was true: your mom had an amazing butt. It was humongous and perfectly round without a bit of sag for someone her age. Compared to most girls you've met your mom's ass was on a whole other level of size. Her huge rump had a plump sexiness to it, and when she started doing yoga that only improved its shape. When she walked around in a tight dress or form-fitting jeans it turned people's heads. You had to turn away whenever she went upstairs to keep yourself from staring.

Not letting yourself get distracted, you got out your portal device. You created a large portal next to yourself to step through and aimed for where to place the small exit portal. If you to put it on the floor, there was too much of a chance of your mom accidentally crushing or sitting on you. You needed somewhere around head-level to get her attention. Next to her yoga mat was a large wooden dresser, perfect. You made a small exit behind a framed photograph so she didn't see the portal.

Stepping through the portal, you left the other side an inch tall. Well, at least for now the device was operating normally. Next you closed the portals so nothing else came through. Walking out from behind the picture frame you saw your mother who now looked like a giant. She stood up fully, taking a short break between exercises. Her body towered over yours, casting an ominous shadow. She was standing right next to your tiny body, but still facing the other way. On top of the dresser you came up to about her rib cage. Looking up you saw her head, which looked really far away. Looking down you saw her gigantic booty, which was even more massive and overwhelming at your new size. You could now see the outline of her panties through the yoga pants as they clung onto her butt.

Again you forced yourself to look away from her mesmerizing ass. You chose now to bite the bullet and call out to her. Hopefully she wouldn't rip your head off for using a portal device. Right as you were about to yell up to her something unexpected happened. Your mother bent over to grab her water bottle off the floor, bumping her huge butt carelessly into the dresser. The wooden dresser wobbled back and forth causing you to lose your footing. Before you knew what was going on you were knocked off and in free fall. You fell in a straight drop to your mother's lower back, landing with a bump and promptly sliding down towards her butt crack. While she was bent over her hefty rump was sticking out enough to pull the waistband on her pants and panties back, leaving a small gap between her two cheeks for you to slip inside. Gravity pulled you within and once you were completely lost between her ass cheeks your mother stood back up, totally unaware of what just happened.

You reached for your portal device to get out of here but your mother took a step forward. Her heavy cheeks slid you around the inside of her panties and knocked the device out of your hands. Your only way out of this butt prison was ripped from your hands, claimed by the abyss that was her ass crack.

Angela finished her water and stepped forward with a smile on her face, eager to continue her exercise. What did she do next?