I find this unusual but bluepheonix's answer has made it clear, so thanks! And Tibbeh> Isn't Buster a doberman?

1. Buster is not a Great Dane. He is a Rottweiler. (And even if he was a Great Dane, he wouldn't be tiny... those are big dogs..)

2. It's "Angel".

3. Dogs don't care about age. And really, it doesn't matter why he called Angel "his girl" because whatever feelings he had for her, she very clearly did not have for him. Shown by her repeatedly telling him "I am NOT you're girl."

Even so, I believe what Buster said was either just a phrasing (gang slang for family in an essence) or he's acting more like a father figure to Angel. Allow me to explain. When Scamp chose Buster over his father in the alleyway scene, Buster said, "That's my boy!". That phrase is identical to Buster's "that's my girl!" except it's boy instead of girl. That "That's my boy!" phrase also came at a time when Scamp was inducted into the Junkyard Dogs thereby becoming a part of that family. Several gangs and organized crime treat each other as family thereby you would think there are fathers, the leader of the gang, and sons and daughters, the young and new recruits. You may choose to believe Buster's phrase is referring to Angel as his girlfriend but to me, it is just a gang family saying.

Sorry, I forgot to check.

There's too many questions like this, make sure youcsearch your question before you ask