Same question again--why should anyone, homo or normal, have to perform sex acts to obtain spousal benefits?
They don't. There are lots of heterosexual couples who are having no sex. It is not a sex act that qualifies them to get benefits. They have chosen their family structure, and want their family structure to get the same benefits as heterosexual ones. But, how do we distinguish between roommates and couples? That is where marriage comes in. I would be just as happy if we didn't recognize any form of marriage.