I'd like to set a precedence here on "coming out." My mindset on the whole thing involves being honest with people who you feel would be directly and publicly affected by your sexual expression. For example, let's say you're in a collared relationship (either as the one giving the collar or the one wearing it). You can't decide within that relationship on a more "standard company" type collar like a choker or a necklace. (Or you know, get your fine china collar out only for special occasions.)
It's ultimately integral that you wear/have the other person wear something like a dog collar or something with large silver spikes at all times. In that instance, yes, you might consider "coming out" to the people around you. Because they are going to have questions. You can be one of those people who answers said questions as they come, or tries to nip things in the bud by doing a little introductory course. Ultimately it also depends on how important you feel people are to you, and whether they really need to know this about you and how you function in relationships.
Now, let's also say that this collared relationship involves quite a bit of S/m behavior as well. My general feeling - if it doesn't directly impact people around you (example: are you going to be bending on one knee to serve him dinner in a public restaurant?), then it's not up to other people to know about it. General social behavior? Coming out worthy. Very specific sexual behavior? Not coming out worthy. I realize it gets murky because things like LGBTBBQ-ness involve a bit of both. As Frank Sinatra once said, you can't have one without the other. However, letting other people know that you might be bringing somebody of the same gender around is not the same thing as creating a detailed list of all the things you like to get involved with between the sheets.
For example, I "came out" today to my mother about Frisbee. (I've decided to start capitalizing these, as it's difficult otherwise to distinguish between a verb and a proper noun.) He's going to be coming home with me in about a month, my mother will most likely meet him, and I didn't want to do the bullshit, "oh, this is my 'friend.' You may notice I hold hands with and sometimes kiss my 'friend' on the mouth, but don't worry. It's nothing we need to discuss." Ultimately, she doesn't need to know the specifics about it. That we met at a gang bang. That I see him usually about once a week, and that I like the taste of his dick in my mouth. All she needs to know is that she is going to meet him, and I'm going to interact with him publicly in the same way I do Now-hubby (i.e. hand holding, cuddling, kissing), and that we're all adults and okay about it.