I put "other." My husband is aware I have relationships outside the marriage, but he insists on Don't Ask, Don't Tell. If I get to a point with someone where strong emotions are involved, as in I want to spend nights, I want them more involved in my life, I am to tell him, and we'll take it from there. At this point, he wants no involvement with my lovers. He would much rather I confine myself to women, as he is fairly comfortable with the idea of me with another woman, less so the idea of me with a man. However, that's not a "rule," just his preference.
I don't love DADT, but we've only been "open" a bit over a year, so I'm hoping for a bit more openness in the future. I'm willing to experiment within these confines for now. Throughout my early twenties, I had several completely open relationships, and those were a bit too much for me. I require a lot of attention, and I felt unsafe and unloved with partners who had several other partners. Of course, I was young then and didn't know how to set boundaries very well. Still, I think my ideal would be to have just two committed relationships, with stable metamours. For example, I could see myself happily dividing my time between my mono husband and a long-term girlfriend who has a spouse. But who knows how this will all work out.