Three Strange UFO like Clouds/Unexplained Aerial Phenomena

O.k. so this is easyJet flight EZY810 from Edinburgh (EDI) to London Gatwick (LGW) on Sunday, 15th February 2015 and it's 15:17 GMT, about 20 minutes into the 70 minute flight. Flight level is 33,000 feet. I'm looking out of the window to the west and I see what appear to be three small clouds but in my 40 years, I've never seen clouds flying in formation! So I whip out my iPhone 5S and take a video clip of them. They're not reflections; watch as the clouds disperse over the duration of the clip. Wierd or what?