Everyone Deserves Love and Happiness

Questions about how to answer someone who says, “Everyone deserves love and happiness,” in response to objections to same-sex weddings, and how to think about same-sex adoption when looking through the lens of the greater good.   How would you answer someone who said, “Everyone deserves love and happiness,” in response to my objections to same-sex weddings? How should I think about same-sex adoption when looking through the lens of the greater good? If same-sex marriage is legal, what is the greater good in terms of children—giving a child a home or fighting against same-sex adoption ever occurring?