I also talked about Blaine wearing a leather motorcycle cap. As RM (Letters from Titan) said, that marks someone being a Dom in formal Leather culture. I knew that cap meant Dom, and remembered a phrase about "earning your leathers." I had other people I could ask about it, and reading material to refer to. Blaine put the cap down, which is probably just as well. I don't think the other members of New Directions got the BDSM reference. Obviously the censors didn't, and large parts of the audience probably missed it. He went for big arena rock and roll, keeping a sparkly leather jacket on, but it wasn't magical. He stayed in the choir room.
Blaine went very visibly gay with "Don't Stop Me Now," too. ND got that to some extent, and accepted him. The bros, even the new ones, are okay with him being gay. The rest of ND was participating in the song. They were into it.
Blaine was himself with Tina at his house, confirming that he's gay. It was back to his usual needing to out himself. There's discussion of Blaine not knowing who he is, but he's sure about being gay.
Tina got Blaine back to acting like the heteronormative gentleman, but that's not really who he is. Not that Blaine doesn't have manners, because his manners are usually better than the rest of the glee club's. It's just that he's playing a role when he goes along with what a straight man would do in those situations. And there's only so far he'll go with what a straight man would do.
So Blaine tried on different outfits and mannerisms, mentally and in what passes for "reality" on Glee. In the choir room, he was accepted when he acted visibly queer. The older members of ND were used to Kurt. Jake and Ryder followed their lead, though Jake and Ryder didn't seem to be homophobic in the first place. Blaine trusted them to support him when he fell back, and they did.
Blaine presumably knows as much about gay culture as a smart boy with plenty of computer access and considerable motivation would. He tried portraying different sub-cultures. They weren't really him, but he was experimenting with how to make himself more visible.