If people are misinformed, you just have to educate them. I usually start by saying "Darwin, Einstein, and Queen Victoria all married their first cousins, so I think I'm in good company." We don't advertise that we are cousins, but it usually comes up with friends in the "How did you meet?" conversation. We just tell people simply and directly when they ask. They are usually mildly surprised, many people then tell us about a cousin crush they've had. It hasn't happened, but if anyone reacted with shock and horror, I wouldn't want them as friends anyway.