I don't deal with it. I tell people on a "need to know" basis. Or if I feel they will handle it well. Most of my friends know, with the exception of people whos friendship is based more on their child's relationship with my son. I don't feel a need to tell them since the friendship on our part is more superficial and the only person who will be really affected by their opinion is my child. Quite a few of my family members know. I've told the ones I know are more accepting. But there are others in my family who still think interracial marriage is taboo-forget gay or poly or anything else. Aside from my father (who thinks this way) I really have nothing to do with those relatives. My dad I haven't told directly but I try very hard to break down his prejudice whenever I get the chance. He's accepting my husband is Hispanic and sis's fiance is black so it's progress. People I CHOOSE to have in my life for myself know. Because I chose them in part for their open minds and acceptance of others. I try not to associate with judgmental and closed minded people whenever possible. And no one needs to know whom I don't want to tell.
Right now my husband and I are again in a mono relationship, so it isn't a big deal not to run around being open about poly. Should we form another relationship we'll worry about it then.
I'd rather be hated for who I am than loved for who I am not.