If you offer benefits to legally married couples, you have to offer benefits to legally married couples.
Any HR goon can tell you that.
And when the Nazis tell you it is illegal to patronize the Jewish shops you obey the law.
Good point. One solution is to end "spousal benefits" to couples, period. But it would take integrity and principle to do that, and we know those are foreign concepts to Indiana's biggest combination bath house-and-abortion mill.