You can keep ignoring that "homosexuals" as a classification are people who identify themselves based on a sexual fetish.
People who want to eat horse meat in America are prohibited from doing so by law (even though horse meat is processed for export for human consumption in America).
If the government cannot regulate what goes on in the bedroom (but can legislate how much water your toilet flows in your bathroom), why are there any age of consent laws?
We know that teens are having sex (and underage sex used to be prosecuted as statutory rape). We know that adults are having sex with teens below the age of consent and that states make exceptions in the law for "Romeo & Juliet" (and now "Romeo & Romeo") cases where the adult is within 4 years of the minor below age of consent.
Therefore the persons consenting to legal sex acts are not "consenting adults". And those who are both below age of consent are definitely not considered legally able to "consent". In rare cases (say a 14 year old and a 10 year old) it will be considered molestation or statutory rape but the difference in age (not "maturity") is no different than the exception made "later" in the underaged teens years.
These would still appear to be "morals" sex laws.
Either the government has jurisdiction there or it doesn't.