This little dog doesn't want anyone kissing his mom! It's no surprise that he has a close bond with her, but it seems like he's a little over protective. He doesn't want anyone getting any kisses except him.
Dogs are great at reading our emotions, and they also express many of the same emotions that we do. Just like us, they can get jealous for many reasons, but the most common is because they love you and want all your time and attention. When they see you giving someone else attention or affection they react much like a child would; selfishly.
This little guy isn't alone in the jealous department, but his parents obviously think it's pretty adorable. The way his dad teases him is so adorable. Wouldn't you tease your dog if he got jealous too?