While Chief Justice John Roberts was swearing in President Obama at today's inauguration, New York Senator and inaugural MC Chuck Schumer mugged a bit for the cameras. According to a progression of photos captured by Reuters photographer Jim Bourg, you can see Schumer smiling behind Malia Obama, realize he'd been caught, and then try to hide behind Malia again.
Anyway, it's already a (slightly forced) meme! For example:
While the Schumer photo isn't technically a photobomb — Schumer had every right to be in the photos, after being side-by-side with the president for much of the morning — the series above suggests that Schumer was very aware of what he was doing, which is meme-worthy enough.