In the context of a terrific, in-depth Daily Beast Q&A about his life and career by Tim Teeman, Michael C. Hall opens up about playing gay characters, responding this way when asked if he himself has ever had any gay experiences:

I think there’s a spectrum. I am on it. I’m heterosexual. But if there was a percentage, I would say I was not all the way heterosexual. I think playing the emcee required me to fling a bunch of doors wide open because that character I imagined as pansexual. Yeah, like I made out with Michael Stuhlbarg every night doing [Cabaret]. I think I have always leaned into any fluidity in terms of my sexuality.

But pressed on the issue, he clarified:

I’ve never had an intimate relationship with a man. I think, maybe because of an absent father, there has definitely been a craving for an emotional intimacy with a man. I don’t mean to suggest that an emotional relationship between a father and son is any way homoerotic. I mean an emotional intimacy or connection that at least in the milieu I grew up in was considered fey. I had an appetite to have emotional connections with men beyond beer, sports, and fist pumping that were considered “gay.”

So you're straight playing gay — got it! (And that's okay, but the odd insistence that he's somehow fluid feels like a stretch, no?)