Cheese! Riley the smiley dog celebrates his second birthday with a toothy grin and a cupcake

A year ago he bow wowed the world with his joyous grin and now Riley the smiling dog has done it again on his second birthday.Owner Maureen Ravelo couldn't resist throwing another party for her pet with amazing human-like expressions a year after he grinned through his first.Once again the happy hound celebrated at Maureen's home in San Jose and this year Riley seems to be throwing his head