Well, if you're going to have someone photobomb your engagement, make it Celine Dion! Celine Dion witnessed a proposal happen right in front of her at a meet-and-greet last Friday at Caesar's Palace in Las Vegas. After the first photo the boyfriend got down on one knee and asked his girlfriend to marry him. Celine was just as shocked as the girlfriend when he asked! Take a look at how it went down.