At the beginning of season 13, Mac is, finally, an openly gay man. He spends most of the season uncertain of his place in the world, up until the finale, "Mac Finds His Pride." Mac, having never come out to his father, is encouraged by Frank to do so. The episode brilliantly uses the dichotomy between Mac and Frank as a catalyst for contemporary issues; Frank's bigoted understanding of the LGBTQ community being a major theme.
At the end of the episode, Mac finally comes out to his father courtesy of some sort of emotional interpretative dance. Mac's father does not approve.