He's the lead guitarist of the Australian band 5 Seconds of Summer.
Recently, tweets from 2012 resurfaced that showed him using sexist, anti-gay, and other offensive language.
One Twitter user tweeted the screenshots of his alleged sexist tweets, where he tells someone who's "hopeless in the kitchen" to "get a woman."
The person also found screenshots of him using the anti-gay f-word.
The Twitter user added that Michael has not apologized for wearing this shirt that has the Confederate flag on it:
Well, on Saturday, Michael issued an apology on Twitter. "I am so fucking sorry for all the dumb shit I did when I was younger. I am a different person now with a much better understanding of the world," he wrote.
"I am so sorry for hurting anyone," he continued. "It was never my intention. I was so naive, and I am embarrassed and I am beyond sorry. I will continue to be better and I will continue to change. I never want to hurt anyone again."
Michael has not addressed specific claims of sexism, homophobia, or racism, but we will update you if he does.