MJ and NAMBLA members "love" under aged little boys, suppose they should get to marry the ones they "love" as well? Or the persons that "loves" their pet? ETC--- The child or pet could consent therefore making it a consentual agreement.
On the question of choice, it must be noted that all sex but rape* (*on behalf of the rape victim) is voluntary and thus every sexual act involves a conscious choice. A person's inclination toward a form of sexual conduct may not, for any number of reasons, be consciously chosen, but the mere existence of desire does not justify the act. To accept otherwise would be to validate adultery and pedophilia. Society has the right to require people to suppress harmful desires, even if it is difficult for them to do so.