At a party rally in Sardinia on Saturday, the media tycoon received the blessing of television preacher Massimiliano Pusceddu, who thanked him for opposing gay marriage and defending family values.
"Thank you dear Father Massimiliano, I'll try not to let you down and I promise you two and a half months of complete sexual abstinence until April 9," Berlusconi replied, in comments reported on Sunday by the daily Il Giornale.
The twice-married Berlusconi, 69, prides himself on his physical fitness, and after a facelift and a hair transplant he looks younger now than he did when he swept to power in 2001.
He has often been criticised by commentators and feminist groups for his use of sexual innuendo and sexist jokes.
In June he sparked a diplomatic incident with Finland when he said he had used "playboy tactics" to persuade its woman president to give up a bid to site the European Union's food agency in Helsinki rather than the Italian city of Parma.
In a news conference in 2002, he famously complimented Danish Prime Minister Anders Fogh Rasmussen for his good looks.
"He's so handsome I'm even thinking of introducing him to my wife," Berlusconi chuckled, in a reference to political gossip at the time that his wife, a former actress, was having an affair with a well-known centre-left politician.