To be someone's "puppydog" means to be completely head-over-heels for them. Loyal, unconditional, and unwavering. Quite often, as in like the love of a puppy or dog, the person who is "puppydoggin'" might not be treated as well as they should be... but keep on forgiving, and adoring whomever they're in love with ...no matter what.
by Ms.Rhart June 15, 2009
Those two men are puppydoggin' it.
by Jon Wolfe November 04, 2007