Justin Bieber hangs with Mike Tyson in the gym.

There are few pairings that seem stranger than Justin Bieber and Mike Tyson, but Gwyneth Paltrow's kids call Jay-Z "Uncle Jay" so I guess anything's possible. Tyson uploaded this photo to Instagram Sunday and tweeted, "Me, @johnny and @justinbieber before we started training JB."

There are lots of things to note here besides the fact that now you know Mike Tyson's on Instagram: First, is Bieber becoming a boxer? Maybe after his run-in with the paparazzi this weekend he decided he needed to up his self-defense game. (If this means we get to see Biebs in the standard boxing get-up on the regular, we cosign this new hobby.) Second, WTF did Mike Tyson and Justin Bieber talk about? I bet "The Hangover" made up the majority of the conversation. "The Hangover," and how good "Boyfriend" is -- we can see Tyson getting down to that ish.

Photo credit: @MikeTyson