If you've ever wondered what it would look like to see a person sing a duet with themselves, here you go. Watch as Weight Watchers spokesperson Jennifer Hudson sings a duet with her former, weightier self for one of the company's new ads. Through the magic of technology, Skinnier Jennifer and Heavier Jennifer belt out Whitney Houston's "I Believe in You and Me" in tandem, and while the ad definitely highlights her 80-pound weight loss, it's also a little unsettling. It's not the contrast between her two looks that's the issue, it's the fact that their duet violates the rules of the space-time continuum — kind of like that time Natalie Cole sang a duet of "Unforgettable" with her late father, Nat King Cole. It sounds good in theory, but in practice it makes your brain hurt a little bit.