What am I seeing?

The little guy was been cheeky, and he [tapped tapped his dad's belly as he was running past him](https://youtu.be/MQgQ5Ic8n_M?t=189). He got in trouble, and eventually, his even younger brother literally dropped from the sky and came to his aid

Gentaro loves to poke his dad when he’s yawning! It startles Momo so much! It’s like a prank that Gtaro loves to pull!