131,729 married gay couples

From the AP:

Increasingly visible, the number of gay Americans telling the U.S. census they're living with same-sex partners nearly doubled in the past decade, to about 650,000 couples. And more than 130,000 recorded partners as husband or wife....

That 2010 tally of married gay couples is higher than the actual number of legal marriages, civil unions and domestic partnerships in the U.S. Even after New York legalized gay marriage in June, a Census Bureau consultant, Gary Gates of UCLA, put the actual number of legally recognized gay partnerships at 100,000.

"There's no dispute the same-sex population increases from 2000 and 2010," said Martin O'Connell, chief of the fertility and family statistics branch at the Census Bureau. In cases of couples who reported they were living in a marriage relationship, "they basically responded that way because that is truly how they felt they were living."