The beautiful but heartbreaking truth about kids and pets is that they grow up -- and, cliché as it may sound, it often happens right before our very eyes.
Ten weeks ago, we met Theo and Beau -- the puppy and toddler whose magical friendship has been faithfully and irresistibly documented on Instagram by their mom, Momma's Gone City blogger Jessica Shyba. Back then, Beau had not yet turned 2, and Theo, a rescue pup, was still a small, snuggly-snouted ball of fur. In the weeks since, Beau has celebrated a birthday and Theo, as you can see, has grown to just about the same size as his human brother.
If you don't remember what these two cuties looked like in the olden days, here's a cheat sheet. For even more adorableness, visit @mommasgonecity on Instagram -- and put their upcoming book on your reading list.