Numerous media outlets, including People, have confirmed that the parents of two have yet to tie the knot.
Ryan, 35, and Eva, 42, started dating in 2011 after meeting on the set of the 2012 drama The Place Beyond The Pines, and have two daughters together; two-year-old Esmeralda Amada Gosling, who was born in September 2014, and Amada Lee Gosling, who arrived in April of this year.
The couple managed to keep both of Eva's pregnancies a secret until the last minute, with the news that they were due to welcome their second child only emerging two weeks before the actress gave birth.
"I'm a lucky man," Ryan, 35, said of his little family, while attending the Toronto International Film Festival earlier this month. "We couldn't be happier, they are so sweet."
The notoriously-private pair work hard to keep their personal lives out of the spotlight – although Ryan did open up about his happy home life in a recent interview with Hello!.
"I know that I'm with the person I'm supposed to be with," he sweetly said, before adding that the only quality he looks for in a woman is "that she's Eva Mendes. There's nothing else I am looking for".
Eva, meanwhile, has said in the past that she wasn’t planning to get married or have children – but "with Ryan things are different", a friend told People. "She's very independent, but she's content with her partner. She has finally found the person she really wants to be with."