Marriage has been redefined for thousands of years.

Matthew 19:8 (AV)
8He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so.

And certainly the serial monogamy we have turned marriage into here in America has redefined it.

Before that was the "it's okay to cheat" mentality (typically reserved for the husbands).

News flash: ANY deviation from the course God chartered for sex and sexuality (and marriage) is a perversion!

We lesser perverts get so up in arms about the greater perverts, don't we!