By Mollie Quirk Leonardo DiCaprio has sparked engagement rumours as his girlfriend Vittoria Ceretti is spotted with a massive ring on her engagement finger. Vittoria, 25, flaunted the massive sparkler on her ring finger while grabbing lunch with the hunky actor, 49, at Mexican restaurant Yuca’s. The pair were in Los Angeles, with the snaps taken on Tuesday. The Titanic actor has been dating the beautiful 25-year-old model since last year when reports emerged that they were romantically involved around October. And they looked absolutely smitten earlier this week in the new paparazzi snaps whil…