I'm sure you've all seen this already, but in case you haven't, you're welcome. Someone posted a different video of them about a week ago, and after watching it I watched this one about 3 days after it was posted. And it has BLOWN UP. Go watch it before it reaches 3,000,000 views so you can say you saw them first. It would be so very hipster of you.
Also, Caitlin, this should have been us. Same age difference and everything. We are like the older, less cute version of them.
P.S. They are 12 and 8!
P.P.S. Watch Maisy sing by herself. It's obvious that Lennon is amazing but you'll just love Maisy after this one.