The case can be made that LGBT+ behaviors are objectively immoral, since like with all generally accepted immoral behaviors (e.g. murder, stealing, lying) they lead to bad life outcomes, and their overall effects on society are negative. E.g. LGBT lifestyles lead to significantly increased risk of physical disease, as well significantly increased risk of psychological disease, and also relatively poor outcomes for children. (Regarding poor outcomes for children, LGBT lifestyles lead to relatively high incarceration rates, and increased levels of mental illness among children of such unions). The most stark effects LGBT+ lifestyles have on society however, can be seen if they were allowed to displace heterosexual relationships and patriarchal families. The above would lead to the abrupt end of our civilization, since among other things, social cohesion would be erased, and procreation would plummet.
In addition to above, parents fighting LGBT+ indoctrination in schools, can make a note that LGBT+ philosophy is tied to a belief system, that suggests that these behaviors are morally acceptable. Parents can object to LGBT+ indoctrination in schools, based on the fact they force on children, a belief system children and parents find unacceptable – similar to gender identity and transgenderism. Also, if LGBT+ behaviors are taught in school to children of Christian or Christian leaning parents, they must be depicted as immoral, otherwise teaching these behaviors would implicitly convey to the children that they are not immoral – consistent with a belief system that is in conflict with that of the parents' and children's. (Note: all of the above instances of LGBT+ indoctrination, violate parents' and children's 1st Amendment rights.)
