Have Mercy! John Stamos reveals his wife, Caitlin McHugh, gave birth to their baby boy Sunday, April 15th.

The new dad is over the moon, posting a photo with his son, Billy on Instagram with the caption,

“From now on, the best part of me will always be my wife and son. Welcome Billy Stamos.” #NotJustanUncleAnymore#Overjoyed

The little man is named after John’s late father.

https://www.instagram.com/p/BhnqDhqhKPg/