My guy smiles a few times a day, but rarely smiles AT us or our attempts (blowing raspberries on his tummy, funny faces, peekaboo, etc.). Usually he smiles at shiny things, lights, and especially our kitchen backsplash. He's 18 weeks/13 weeks adjusted. Not to say that he seems unhappy during his wake times, he just has a poker face!
Anyone else's LO not particularly smiley? I hope this changes soon because I love his smiles!