Pop star Justin Bieber wants to fight veteran actor Tom Cruise in the octagon. It's unclear why Bieber wants to do so, but he has challenged Cruise to an MMA fight and people are already starting to weigh in on who would win. Cruise, who is more than 30 years older than the popstar, has yet to respond as of this writing and he more than likely won't, since this is so outrageous and not really his style. In a bizarre twist, MMA fighter Conor McGregor has offered to host the event and fight Mark Wahlberg.

25-year old Justin Bieber decided he wanted to fight Tom Cruise late over the weekend, but did not give any reasoning behind it. Maybe he watched the latest Mummy movie? Regardless, he posted the challenge on social media for the world to see. Bieber had this to say.

"I wanna challenge Tom Cruise to fight in the octagon. Tom if you don't take this fight your (you're) scared and you will never live it down. Who is willing to put on the fight?"

Tom Cruise is 56-years old and according to the comments on Justin Bieber's post, the money is on the elder actor to wipe the floor with the pop star. Bieber is more than likely throwing this out there as a publicity stunt to promote an upcoming single. However, Former UFC featherweight and lightweight champion Conor McGregor is now getting in the middle of things and calling out Cruise for not responding. He explains.

"If Tom Cruise is man enough to accept this challenge, McGregor Sports and Entertainment will host the bout. Does Cruise have the sprouts to fight, like he does in the movies? Stay tuned to find out!"

Tom Cruise might be laughing at all of this nonsense right now, or he may not even know about it. This might not even be a blip on the mega star's radar. But, Conor McGregor is taking things one step further and challenging Mark Wahlberg to an MMA fight on the same card as Justin Bieber's idea. This seems even more like some free promotion. McGregor had this to say in his challenge to Wahlberg.

"I challenge Mark Wahlberg on the very same card. Back when mark Wahlberg was Marky Mark, I'd (have) still slapped the ears off him and took my UFC shares back."

There's probably a lot of people who would pay a decent amount of money to watch Justin Bieber and Conor McGregor get the crap beat out of them in the octagon. However, Tom Cruise and Mark Wahlberg aren't going to be the guys to do it unless all of the proceeds go to a charity of some sort. With that being said, let's cut out the middlemen and pit Bieber up against McGregor in a no holds barred MMA fight. You can check out Justin Bieber's Twitter challenge to Tom Cruise below.