New comments on the post and on Twitter, however, are saying that it's not as supportive as MGK made it out to be.
"MGK took this photo in front of the Fall Out Boy audience that was waiting for them to come on stage and do their set," wrote commenter onlyarealmaster. "He was wearing a jacket when he asked the crowd if they would put up their middle fingers for a picture, he turned around to take the jacket off and they had no idea what shirt he was wearing. He couldn't pull a crowd this big, of course they were excited, they were waiting to see the band that they actually paid for!"
"Your shitty rapper was at a fall out boys concert, making everyone take a picture with him without anyone knowing what for or even the shirt he was wearing. As soon as they saw his shirt his ass got boo'd off stage AND HE STILL POSTED THIS PHONY ASS PHOTO," wrote lexi_baby_______.
"Living tha fake Insta-life I guess. We all know what actually happened on that stage.. right?" wrote handy.polished.
Machine Gun Kelly is currently on the road with Fall Out Boy as the opener for the band's M A N I A Tour.
Correction: Upon further review, the video of MGK being originally booed was doctored and is indeed fake. Check out the real video below of his performance below.