Thanks everyone for the great advice and other "BITING WHEN LEAVING" stories. Nice to know Biggie's not the only crazy dog out there.

hehe jk!
but just an update: I tried a few things such as having Biggie on a leash and having a friend "pretend" to leave over and over after a while Biggie didn't seem to care? But I don't know if it's because it was so repetitive he stopped caring and figured he knew what was next???? The next day Biggie carried on getting mad at me when I left home. So I think if I continuously enforce training him on a lease he'll eventually get over it. Anyone else have ideas? I'd love to hear them! Next I also plan on training Biggie to walk next to me or behind me on a leash. Also when walking out the door I should be first!! Slowly but surely I'll become the pack leader!! Wish me luck everyone!