Actor Seth Rogen was left fearing a father's wrath on the set of his new movie Neighbors after delivering dialogue from the racy script in earshot of an eight-month-old baby.

Rogen and Rose Byrne play new parents struggling to live with rowdy residents next door in the upcoming comedy, and the real life dad of the baby used in the movie was ever-present on set.

The Knocked Up star admits it was uncomfortable reciting some sections of the script with a baby in his arms, and he feared the little girl's father would become protective and intervene.

Rogen tells U.K. talk show host Graham Norton, "She was the Daniel Day-Lewis of babies but I'm banking on the fact she was too young to understand what was being said. Or if she did, I hope she takes the money she earned and spends it on therapy!

"There were a few times when her father was horrified!"