Most Helpful Guy
Unless the house is very dirty, he's making too big of a deal about it. And hearing a mouse? Lots of houses have mice this time of year, it doesn't mean the people living in the house are doing something wrong. He's over reacting. You said he stormed out and was mad. That's ridiculous. You may want to consider getting in a relationship with someone who is more reasonable.
Most Helpful Girl
He's just a jerk. Even if he has a problem with something he shouldn't act that way and storm off. I grew up in a similar situation. Our house was pretty much a shack. There were holes every where, bugs, rats. I dated multiple guys during that time, and none ever complained about it. If he cares about you, his only concern should be helping you get yourself in a better situation. I know you care about him but chances are he's going to react that way to many things as your relationship progresses, and probably going to get worse and worse. Sounds like the red flags at the beginning of an abusive relationship. Get yourself out, and find someone better. You deserve it.