The number of same-sex couples recorded as living together in the UK rose by more than 50% in the three years to 2018, official statistics show.
The Office for National Statistics says there were 232,000 in 2018, compared with 152,000 in 2015. And more than a quarter of them were married.
There were also eight million people living alone, more than ever before.
And this has been driven by increases among women aged 45 to 64 and men aged 65 to 74 years.
The figures also reveal one in four 20- to 34-year-olds - 3.4 million in total - was living with their parents.
And opposite-sex couples "increasingly choose to live together before, or without, getting married".
An ONS statistician said much of the increase in same sex couples recorded as living together had been driven by the legislation introducing same-sex marriages, whether this meant more same-sex couples were living together or more felt comfortable to say they were.
LGBT Foundation communications coordinator Joe Nellist said: "It is positive to see that more same-sex couples feel confident and able to disclose their relationship and household status.
"We have made significant developments in LGBT equality legislation, including marriage equality in England, Wales and Scotland, which has given more LGBT people the confidence to live their lives openly.
"It is important to remember that if we're not counted, we don't count."
But he added many LGBT people were still a long way from being able live out their lives as fully equal.
The ONS statistics are calculated from the official labour force survey, which covers 40,000 individuals.