We were totally closeted for a long time for a few reasons. We run in very conservative circles, for one. Also, our situation was more that I was poly and dating and DH was mono - so he didn't feel there was any benefit to him in us coming out, yet also felt it could cost him in terms of social status.
Then, we ran into a situation with some good friends in which being closed to them caused really terrible relational issues (I won't bore you with the details). After that, we decided to start telling people...slowly.
DH let me come out to my BFF, which was really hard. She is very open minded, but I also just sort of dropped the information like a bomb without warming her up to the idea, so it didn't land well.
Then, we came out to my siblings, which was easier since they are 1) not christians and 2) my brother and his wife had experimented with poly a year or so prior, so that part of the family was more familiar with the concept and didn't require as much education. It was actually pretty awesome, because my siblings (all younger) told me they look to DH and I as the model of a healthy marriage (ah, shucks :P ). My sister told me she had basically given up on having relationships because she would date a totally awesome guy for a year, then meet someone else she was into and have to choose. She wants to get married and have a family, but she didn't feel she could be monogamous her whole life, and didn't know there were other viable options. When she saw that we had a healthy poly marriage, it gave her hope. Yay!
Then DH and I both made Ok Cupid profiles, and once he got a date he was much more amenable to the idea of being totally un-closeted. He told his best bud, which went well. Just this week he ok'd me to finally post pics on OKC.
My hope is that eventually, it just won't be an issue. I fantasize about conversations with people where I mention my boyfriend, they look at me cross-ways, and I just say "oh, yeah, DH and I have been open like forever" like it's no big deal. I don't need to scream it from the rooftops - but I am kind of weary of calling my boyfriend "this guy I know" and ducking church-mates when I'm out at the bar with him.