My fiancee and I are in an open relationship, and have been for quite some time. It's wonderful and I don't think I could do any other kind of relationship; I'm more happy than I've ever been in my life, and so is she. Her name in this story is Zoe. To make imagining our appearances easier, we look and sound like Archer and Lana from the TV show Archer. So much so that Zoe made me promise we'd go as them next Halloween since we didn't last year.
I am not new to threesomes, and had a female-female-male threesome with Zoe a long time ago. But I've wanted to have a male-male-female threesome with Zoe for a long time and we haven't because it's been a lot harder to find the right guy; most guys are either not my type or not Zoe's type or weird about bisexuality. Both Zoe and myself are on some level bisexual ("bisexual but not biromantic" was how a friend described it), and every person we've wanted to threesome with has been as well. The kind of guys who avoid contact with other guys during threesomes are not the kind of guys I want to be doing group sex with because then we're competing for pleasure as opposed to encouraging it in each other; on the flip, though, it's difficult to find bisexual guys who she's physically attracted to because she's not physically attracted to skinny guys who don't lift, and skinny guys who don't lift are most bisexual guys we know.