Why can't Cardinal Juan Sandoval Iñiguez stop talking about sex?

Cardinal Juan Sandoval Iñiguez of Guadalajara is taking a few pages out of the play book of the truly wackiest elements of the U.S. Republican Party. Remember when former Senator and now presidential hopeful Rick Santorum a few years ago compared gay marriage with "man on child, man on dog"? He was not reelected. Former Arizona congressman and possibly even more utter lunatic J.D. Hayworth a few months back resorted to the same argument, warning that a Massachusetts Supreme Court ruling put marriage under threat and could lead to man-horse nuptials. 

Cardinal Sandoval has now joined the fray:

"If what the [Supreme] Court is defending is a right of adults, then, over time, adults could be entitled to claim the right to establish any relationship with anyone, person or animal. (And for the record, we are not equating homosexual relationships with the relationships between animals, because there are plenty of those who would want to interpret it this way)"

Exactly who would interpret it this way, cardinal? On what authority do you make these claims? 


Or rather, what explains Cardinal Juan Sandoval Iñiguez increasingly bizarre obsession with sex?