What would you do or say if your child wanted to be lesbian/gay?

Don't make the mistake of mixing right/wrong arguments with what you personally agree with. That's a way of making thinking easier. Found the following online:

"One psychoanalytic hypothesis for the connection between poor early father-son relationship and homosexuality is that during the critical gender-identity phase of development, the boy perceives the father as rejecting. As a result, he grows up failing to fully identify with his father and the masculinity he represents...

One likely cause for 'failure to identify' is a narcissistic injury inflicted by the father onto the son (who is usually temperamentally sensitive) during the pre-oedipal stage of the boy's development... The hurt manifests itself as a defensive detachment from masculinity in the self, and in others. As an adult, the homosexual is often characterized by this complex which takes the form of 'the hurt little boy."