"My son/daughter is gay/lesbian because I am gay/lesbian." -predatory child sex abuser
Adults do not always know their sexual identity.
Children should not be expected to know their sexual identity.
Children of bisexual parents who are also bisexual, are the result of encouragement to identify as bisexual, to re-affirm the parents own sexual identity.
Targeting children expecting them to know for certain in a way which is criminal to do so in adults, is child abuse.
A child who has a very well defined sexual identity is a result of parental encouragement, indoctrination, which is child abuse.
Children do not even know fully what sex is before puberty, much less their preferences.
This is especially pronounced within LGBT+ communities.
In any other topical arena, the parents pushing their own prejudices onto children would be noted as sinister and discouraged.
We do want children to have open minds, but we also want parents to have open minds, instead of permitting the pressuring of children into becoming something they might not naturally be.
Targeting childrens sexuality is only going to cause confusion and disruption from whatever the person naturally feels inclined to be. This is why it is recognized as abusive.
Disclaimer: The writer is not anti-lgbt. The writer is anti-abuse. Where the lgbt flag is waved to protect abusers and enable them to get away with it, because lgbt are a protected caste; the abuse is still abuse.