Mary Cheney, the daughter of former Vice President Dick Cheney, married his longtime girlfriend Heather Poe.

The couple, who had been open about their relationship, married Friday in Washington D.C.

"Very happy to announce that as of this morning, Heather and I are legally married (at least in DC), 20 years to the day after our first date," Cheney reportedly said on Facebook, according to People magazine.

Cheney, 43 and her wife have two children together, Samuel, born in 2007 and Sarah born in 2009.

Cheney was open about her sexuality since Dick Cheney was Vice President in the George W. Bush administration.

"Mary and Heather have been in a committed relationship for many years, and we are delighted that they were able to take advantage of the opportunity to have that relationship recognized," Dick Cheney and his wife Lynne wrote in a statement.

"Mary and Heather and their children are very important and much loved members of our family and we wish them every happiness."

Cheney and Poe reportedly met in 1988 while playing ice hockey.

Washington D.C. legalized same-sex marriage in 2010. Currently six states and the District of Columbia allow same-sex marriage.