When you have a small problem that is supposedlyeasy to fix, but can’t due to how hard it is to explain the problem
Biology teacher: You have a missing cell lab assignment in my class
Me: But I just turned it in yesterday Biology teacher: Yeah, I didn’t get any assignments from you
Me: Did I forget to put my name on my paper? Did I turn it in the wrong time?
Me: Darn it. I got a mouse in the house
Mouse in the house is when your penis is too small to have sex with a girl, so for her pleasure, you tie the tail of the mouse to your small penis and have sex with her.