During an after fight interview, Connor McGregor admits that he doesn't even know who Machine Gun Kelly is!! All he knew was that he was with Megan Fox which leads to the assumption that he probably made a comment or asked for a picture with Megan rather than MGK!
I mean Megan looks great and she came to the VMA's dressed in a see through gown so it's easy to assume that folks are going to say stuff to her and possibly want a pic!
The original assumption was that Connor McGregor wanted a photo with MGK and he refused and that's where the fight stemmed, apparently not!!!