What is wrong with him? 

One of the hardest things about living with other people is agreeing on a standard level of cleanliness. Everyone grew up in a different environment where «clean» meant something different. For some people, «clean» means there is no literal trash on the ground, and all the crumbs on the floor are perfectly fine to stay because they’re smaller than an empty Mountain Dew bottle. For others, a single pillow out of place is so upsetting and distracting that they need to fluff and rearrange the pillows on the couch every time someone uses it. Most of us are somewhere in the middle, but know people who have lived in the lands of these extremes. 

The man in this story is a textbook slob, and he always has been. His fiancée is trying to incentivize him to change, but it’s not going anywhere.