Let's start with "I'm coming out" from under the rock you've been living under... ;) When a person says he or she is "coming out," it usually means being straightforward about his or her sexuality (gay, bisexual, etc.). Further, since homosexuals are technically not allowed to get married in most states, their significant others are referred to as "domestic partners." But usually only on paper. I know gay couples that refer to each other as husbands.
In Oregon State - since February 2008 ( supreme court, fought of John McCain / Arizona State from blocking the Marriage for just about anybody... judge threw it out. 'An Outsider, who doesn't live in the State can't be grounds for holding up Civil Rights of others to get Unions, and Benefits.)
Domestic Partner is a fancy way of referring to your pet - usually a canine.
"I'm coming out" is what our children say when we've asked them not to peek as we wrap their birthday presents. It is usually said just before their bedroom door opens, and then again as they mosey in your direction, and repeat it through loosely spread fingers against their face, with a big "v" around their open eye, as they turn their body away from you but crane their head toward wherever your workspace is.
domestic partner usuallymeans ur a homosexual who is living together and/or has had a sortof 'wedding' ceremony. Coming out means ur letting everyone know ur gay or lesbian rather than continuing to hide it