Sinead O'Connor Nothing Compares 2 Her 4th Wedding

12/9/2011 4:45 AM PST

Although she once claimed to be a lesbian, controversial singer Sinead O'Connor celebrated her 45th birthday by marrying a man for the fourth time at a drive-thru wedding in Las Vegas yesterday.

Wearing a demure tattoo-revealing low-cut pink gown, Sinead walked down the aisle back of a Cadillac with fiancé Barry Herridge, 38, at the notorious Little White Wedding Chapel -- the same spot Britney Spears said I do to Jason Alexander in 2004.

As the happily married couple exited the chapel ... no one threw ripped up pics of the Pope.