Happy endings are so rare on Grey's Anatomy, so let us savor this moment.
Tonight's episode went back in time to 2007, when Owen, Riggs, Teddy, and Megan were all in the army, when Megan was waiting to find out if she ranked high enough to get promoted and Riggs had just cheated on her. When she found a fancy necklace on his floor, he took the opportunity to propose with a joke about how she loses all her rings.
In fact, Riggs had panicked, and it wasn't a necklace for Megan. It was actually the engraved necklace of the girl he was cheating on her with, and sooner or later she was going to figure it out.