Someone, mainly females who stick around in an emotionally abusive relationship with a compulsive cheater. Due to the cheater keeping and treating their mate as their pet the mouse stays regardless because it's the only love she receives. Even though deep down they know that love for them is superficial or even fake they convince theirselves that it's real. They deal with the partners cheating manipulative ways just like a good loyal little pet.
Who cares, your girlfriend is a mouse. Therefore you can literally do whatever you want knowing she will never leave you. You can probably bang another girl in the next room and she wil turn away and possibly cry but she won't do nothing about it cuz she's a mouse, you got her pinned down so she ain't going nowhere
Ugh! He is such a Mouse.
But Katy is a huge Mouse, she never listens to me.
1. A THING THAT HAS A USB TO CONTROL YOURS OR OTHERS MOUSES ON THE SCREEN
2. a cute little harmless thing THAT CARRIES DESSISSES