Unusual

Mention same-sex unions and some people will cry out that it is “unnatural”. What makes something “unnatural”, and not just merely “unusual”? If you believe, as I do, that homosexuality is a genetic trait and not a behavioural choice, then are same-sex unions any more unnatural then redheads or people who enjoy rock climbing? Usually, men and women fall in love; less usually same sex couples fall in love. But that does not make it “unnatural”. It makes it unusual.