In this POV style movie, Kim is playing the part of your girlfriend Mommy, and she's decided that she wants you to be her little baby, wearing diapers and using them as they are intended. You're not allowed to use the bathroom and must wet and poop in your diapers while she's at work. She is very strict with her instructions as she puts the diaper on you.
"You're going to use the diaper I put on you, whether you like it of not."
After she diapers you, Kim leaves for work, but when she gets home she's very cross to find that your diaper is still dry and clean. She had even brought a surprise gift for you, but decides you can't have it because you didn't do what she wanted. She's even more furious when she realizes you have taken the diaper off while she was away and used the toilet.
"Do you know how excited I've been all day waiting to come home to change your diaper?"
Kim's not really sure what to do. She was really looking forward to having a dirty diaper to clean up, and is very disappointed. Since you won't do it, there's only one other option - she's going to have to do it herself, and show you how it's done. So she takes the diaper off you and puts it on herself, then proceeds to fill it with poop while you watch.
"Now doesn't that feel nice?"
But what you're not expecting is that she plans to put the messy diaper back on you! She's going to have a dirty baby boy to look after one way or another, even if she has to mess the diaper herself! She takes off the diaper, and cleans some of the poop off her bottom, and then puts the diaper on you instead before going to take a shower. But before she goes she promises you a very special surprise if you stay in the poopy diaper.
When she gets back from the shower, Kim is very happy that you're still in your dirty diaper. She talks to you like you're a real baby, and as a reward offers you her gorgeous boobs to suck on!