Hee hee - I'd just stay away from "Fella" - might be awkward calling him outdoors "Here, Fella!" Random male pedestrians would be wondering "Why's that guy calling me, I didn't do anything!"

We had an awkward time with the girl across the street after we named a dog Grace. It quickly became Gracie, the human girl's name was Tracy, and as Gracie loved to slick-sneak past us to run loose, there was much confusion when we'd holler "Gracie! Get back here!" Tracy didn't have much of a sense of humor about it, either!