Okay, now seriously, Justin. What does it mean?For the second time in a week, Justin Bieber has shared a throwback couple photo of him and ex-girlfriend Selena Gomez on Instagram . The easy explanation is that he's simply been in the mood to post old photos. He also spent a large chunk of his life with Gomez, so she's bound to pop up in a snapshot or two.The more complicated explanation is that the Biebs is obviously still seriously feeling the SG love. After all, both pop stars have discussed their relationship at length in recent interviews. Bieber has made it known that he still has feelings, even if, especially if, his pop star ex is caught up in rumors that she's seeing One Direction's Niall Horan. It'd be just like the Biebs to stake a sort of virtual claim.At any rate, here's the photo in question.