Rachel McAdams, who has been on-again/off-again with Ryan Gosling, is now bumping uglies with Josh Lucas. While there isn’t a man out there who could live up to the Gos, as he is an irresistible sex god, so we understand that he’s hard to replace. But seriously, McAdams, the next stop on the gravy train is just some B-level boner? It’s like saying those imitation designer body sprays they sell at the dollar store are just as good as Chanel No. 5! Is she slumming it to feel better or just to get some bragging rights? But seriously Rachel, sometimes, being the first one to rebound makes you look like a loser in the game of love. Alas, celebs are not immune losing ground on the breakup battlefield, so here’s a slideshow of the best of the worst boyfriend upgrades and downgrades in Hollywood...