Jason Sudeikis thinks it's "hilarious" when his son calls him 'Dada'.
The 'Sleeping With Other People' actor - who has 17-month-old Otis with fiancee Olivia Wilde - was stunned at how "intoxicating" it felt when the little boy began to know who he was and could say his name.
He said: "He calls me Dada. I think that's hilarious, mind-blowingly hilarious.
"Maybe not hilarious in the conventional sense of a Chris Rock joke, or a Louis C.K. T.V. show, but it's hilarious to me. I never thought that was going to happen and that it would be so intoxicating when it did."
The 39-year-old star and his 31-year-old partner love seeing their little boy grow and develop interests in things like basketball and reggae music, but insist they can't take all the credit.
He joked to People: "We just watched a lot of Bear Grylls. We love ... every second we get with him in our busy lives, and we surround him with people that do the exact same at all times."
He then added: "It takes a village... We have a tiny village known as Brooklyn."
And Jason and Olivia think it is essential to stay in regular contact when they have to go away with their work.
He added: "It really comes down to communication, and using all of these devices that we use too often to distance ourselves, to actually bring us closer together."