In a landmark decision on June 26, 2015, the Supreme Court ruled that the Constitution guarantees a right to same-sex marriage. The deciding vote in the 5-4 ruling, Justice Kennedy said, “Their hope is not to be condemned to live in loneliness, excluded from one of civilization’s oldest institutions. They ask for equal dignity in the eyes of the law. The Constitution grants them that right.”Before the decision, 13 states still refused to recognize gay marriage. President Obama Tweeted, "Today is a big step in our march toward equality. Gay and lesbian couples now have the right to marry, just like anyone else. #LoveWins"
UPDATE: On July 17, 2013 the House of Commons and the House of Lords signed off on a bill that legalizes same-sex marriage. Following that, the bill was given the royal assent by the Queen, which means the law is officially official.