Danny DeVito applies the saying "a watched pot never boils" to his family

In a video shared by AARP, he said: "There's that saying, a watched pot never boils. So I apply that to my kids.

"I look at them all the time, because I don't want them to boil. I want them to take their time and grow...

"I tell my kids that, too. Don't miss a thing. Don't look away. Because when you look back, that kid's gonna be hula hooping."

The 'It's Always Sunny In Philadelphia' star was overjoyed when Lucy and Gracie - who he shares with former partner Rhea Perlman - welcomed son Carmine and daughter Sinclair into the world respectively.

He added: "In two years, my daughters have had a baby each, and since these babies have been born, you gotta tamper me down in the joy department. I'm just like, you know, busting."

Danny pointed out that "the main thing" in life is to have loved ones you can "open up to", and he hopes "everybody" feels the same love he does.

He said: "No matter what happens in your life, the main thing is that you've got family and friends.

"That's all we have, basically: reliable people in our lives who we can talk to and we can open up to.

"I'm very fortunate. Blessing showered down on me, and I wish it for everybody."

Danny married 'Cheers' star Rhea, 76, in 1982 but they split in 2012 before getting back together and went their separate ways again in 2017.

Last year, he admitted the pair - who also share son Jake together - have both "grown" since first meeting in over 50 years ago, and making sure the family is all together is the key to making their relationship work, even though they no longer live together.

He told Fox News Digital: "So the family's growing. The whole family was together. I think that's part of it.

"If you can do that, you know, no matter what your situation is, we don't live together anymore, but we are together in a lot of ways."