You are cohabiting with a bf, right? Not married, but sexually active. And the family members are ok with it, so they are not that staunch - they are already a notch down from the extreme of being staunch. So if you ever need to come out, they won't die a thousand deaths - you will simply tell them to jump a few notches down and away from the extreme. But that only in distant future if you must come out (say, if you decide to have a household in a triad fashion and not a threesome behind close doors). That doesn't seem terribly likely, so just relax.