John Lithgow has likened 'Daddy's Home 2' to a "speeding train".
The 72-year-old actor was made to feel very "welcome" to the set of the sequel by returning stars Will Ferrell, Mark Wahlberg , and John Cena, but he admits he and fellow series newcomer Mel Gibson were just thrown in at the deep end.
He said: "It was like leaping aboard a speeding train. These guys had already done one movie together, two if you count the other one, and they just welcome you into the process.
"They say, 'Come on, leap aboard, we're not stopping for you'. We had a wonderful script and we were encouraged to be creative and improvise when necessary.
"I liked the first film a lot and then I just felt so lucky to be brought aboard."
In the sequel, John plays Brad Whittaker's father Don, and he thinks the bond between himself and Will, who starred as his on-screen son felt very natural.
He told BANG Showbiz: "Will and I are made for each other. Our comedy comes from the same dumb innocent place and you can really imagine us as father and son I think. He just makes me feel funny."
The new film follows father and stepfather Dusty (Wahlberg, 46) and Brad (Ferrell) who join forces to make Christmastime perfect for the children their jointly raise.
However, when Dusty's macho man dad Kurt Mayron (Gibson, 61) and Brad's gentle father Don Whittaker arrive, they turn the holidays upside down.
After a sudden change of plans, the four men decide to take the kids to a luxury resort for a getaway which turns into a chaotic adventure.
Throughout the film, the two father/son pairs come head-to-head after each of them are harbouring some resentment towards each other.