Star poses for pics with wedding couple, then buys a round of drinks.It's not the done thing to upstage the bride on her big day.
But Courtney Jarman made an exception when Lady Gaga just happened to be passing her wedding reception.
And before you could say Poker Face, Courtney and her groom Reece Kerr were asking the New York singer to pose with them in a series of wedding pictures.
Lady Gaga, who was on her way to a show, even popped back to the reception later that night to buy the entire wedding party a drink.
And her parting shot for the couple before she finally left was: "Have good sex!"
Gaga was at the Intercontinental Hotel in Adelaide, Australia, when she walked past the ballroom where the reception was in full swing. Courtney, a big fan, spotted her and screamed: "Wow! It's Lady Gaga."