The consequences of homosexual "marriage" include:
Advancing the normalization of all other sexual paraphilias within society.
Adoption of children into the inherently lesser quality and often abusive "parenting" of homosexual couples.
The advancement of the harmful legal concept that "all behaviors are created equal" and that people are not responsible for their actions (born that way).
Continued assault, in the form of "hate crime" legislation on traditional, moral and religious sections of society and their businesses, as well as the free speech rights of society in general.
These issues are observable in cultures where homosexual "marriage" has been recognized by the state.