The former deputy prime minister confirmed at a fundraising event on Sunday, that he is expecting another son in June, reportedly to be named Thomas.
According to The Daily Mail, his four daughters from his previous marriage to Natalie Joyce, are said to be furious.
A supposed friend of the family told the publication that the impending arrival of another baby brother has reopened old wounds.
The friend told The Daily Mail, "The girls are rightly furious about their father's latest baby news."
The ex-Nationals leader and Vikki Campion welcomed their first Sebastiansitan, in June last year.