Bruce Willis—who turned 54 today—is going to tie the knot this week in the Caribbean with his girlfriend, 32-year-old model Emma Heming, a source tells People. The intimate ceremony will be on the Turks & Caicos, where Willis has a home. Guest villas have been booked and friends, including ex-wife Demi Moore and her hubby Ashton Kutcher, are already there. (More gossip stories.)