Kevin Federline offered female partygoers the chance to be the mother of his fifth child.
The wannabe rapper, who split from his wife Britney Spears last year, grabbed DJ Kid Rock's microphone at Louisville's Felt nightclub and shouted out his unusual chat-up line.
Kevin, 29, said: "I got four kids already - which one of you Kentucky girls wants to have my fifth?"
There were no takers for Kevin's offer, reports the New York Post newspaper.
Kevin, who is the father of 'Toxic' singer Britney's two sons, had complained his VIP table was too small when he arrived at the party on Saturday night (05.05.07).
He allegedly told organisers: "Yo, I need a bigger table - I got six b***hes with me."
Kevin had earlier attended the star-studded Kentucky Derby, where actress Brittany Murphy showed off a wedding ring after reportedly tying the knot with new boyfriend screenwriter Simon Monjack.
Kevin left his girlfriend Shar Jackson - who was pregnant with their second child at the time - when he fell for Britney in 2004.
Britney, who recently spent time in rehab, filed for divorce from Kevin in November last year - two months after the birth of their second child.