Liam Hemsworth reportedly "worked on" Miley Cyrus' father for several months to convince him they should marry.
The 22-year-old actor proposed to the 19-year-old former Disney star last month, with the pair announcing their happy news on Wednesday.
Miley's father Billy Ray Cyrus has already tweeted his approval, although it has been claimed he is hoping the engagement will be a long one.
A new report suggests Liam was determined to show his future father-in-law that they are ready for such a big commitment.
"He apparently has quietly worked on Miley's dad for a number of months, making him realise this is something the couple takes very seriously," reports Chicago Sun-Times.
An insider added: "Underneath it all, Liam is a very solid guy with good, old-fashioned values. At the end of the day, I think that's won over Billy Ray."
Miley's parents have always been close to Liam and like that he is serious about their daughter.
Billy Ray was apparently just concerned the pressures of being in show business - Liam appeared in this year's smash hit movie The Hunger Games - could prove too much for them.
"Billy Ray has always been super-protective of Miley," the insider said.
"While he's become very fond of Liam - as has the entire family - Billy Ray was just worried about Miley still being a teenager On top of that, there's the whole entertainment world thing, where so many young stars get married young, and then it falls apart fairly quickly."
Miley and Liam met on the set of 2009 film The Last Song. They briefly split in August 2010, although it is claimed the break was just so they could be sure they wanted to be together.
Liam popped the question with a 3.5-carat diamond ring designed by Neil Lane. The band is gold and boasts floral patterns cut into it, with small diamonds scattered throughout. The main stone is cushion cut and an antique.
"It was hand-cut around 1880 or 1890 and it's unique and in its original form," the designer told People.
"At that time no two diamonds were alike, as they were all hand-cut, so it's fascinating to look at because it hasn't been re-cut to look contemporary over the years.
"I find that really romantic."