By now you're probably aware that Prince Harry and Meghan Markle are engaged. And as excited as we are to see them tie the knot, they aren't the only celebrity couple hearing wedding bells. Rose Leslie and Kit Harington, Lady Gaga and Christian Carino, and Nikki Bella and John Cena are all getting ready to say "I do," but who will make the trek down the aisle first? Guess we'll just have to wait and see.