Of course it is! Muscle soreness typically occurs when you use stress a muscle and put microtears in it, which then heal and make you stronger. So while we typically think of soreness happening to muscles like the biceps, It can happen in any muscle, including the several in your butt. And since many people tend to have weak glut max’s, it is probably a good thing.
Very Important PSA
It is possible to have sore butt muscles.