According to Life & Style, the two are an item.
“They were at a private beach party – drinks were flowing, one thing led to another,” the magazine reports.
“Next thing you know, they’re dancing together to music, hands started getting frisky and it was a full-on make-out! Everyone saw it!” an onlooker is quoted as saying.
“One girl tried to snap a photo of it on her phone, but Gerard politely asked for privacy,” the source reveals.
Gerard Butler has been rumored to be dating the likes of Jennifer Aniston, Jessica Biel and Naomi Campbell in the past.
For her part, Brandi has been married to Eddie Cibrian. The couple ended in a bitter divorce in 2009 after eight years of marriage and two children, after reports surfaced that he had cheated on her with country singer LeAnn Rimes.
Cibrian and Rimes tied the knot this year in April.