About 150 guests descended on the Las Vegas suburb of Henderson for what was billed as a joint birthday party for Mike Tyson and his wife, Lakiha Spicer, over the weekend, but it turned out to be a surprise "wedding," the New York Post reported Tuesday.

When guests arrived Saturday at the M Resort Spa Casino, the couple announced that it was actually a renewal of their vows, complete with wardrobe changes, a live band, a wedding cake and a candy station.

"Guests were told it was a birthday, but then Lakiha announced that something different was happening. She pulled back a curtain to reveal a wedding setup," a source said.

The ceremony was described as "traditional Muslim," even though it was in a casino and Islam prohibits gambling.

Spicer and Tyson were married in a private Vegas quickie ceremony two years ago. But this time, Spicer changed from a cocktail dress into a mermaid-cut white gown and veil. She switched into another white frock for the reception.

The ex-champ wore a black tux and a satin white tie.