Mila Kunis is insanely hot, talented, and in demand. If for some ridiculous reason you doubt the truth of that statement, refer to her presence on pretty much every publication's list of Hollywood's hottest actresses; her performances in Black Swan, Ted, and Friends With Benefits; and her upcoming roles in movies with James Franco, Clive Owen, Marion Cotillard, and Robin Williams.
Culkin, meanwhile, still looks kind of like he's 13 and has recently been involved in hard-hitting projects like a YouTube video explaining how he transformed his apartment into a painting studio and a film shot entirely on his friend's iPhone. These sound eerily like the things your kid brother might do when he's bored and Home Alone (zing!).
If you heard the rumor they were engaged, we're sure you were just waiting for the moment when she would upgrade.