Secular argument against homosexuality?

Mind-boggling. Really - an argument from 'immaturity'? I know straight couples who are far far more immature. Do you want to start giving 'maturity' tests to people before they get married too? Ugh! Please people, leave a comment or video response. This blows my mind. Here's his letter: MUST ATHEISTS SUPPORT HOMOSEXUALITY? I am a life-member of American Atheists and a family man and I do not support gay rights. I never considered homosexuality unnatural nor immoral, just immature. You doubt me ...