Bella Heathcote has got engaged to her long-term partner Andrew Dominik

Alongside the picture of the three actresses, Bella wrote: "thanks for being born @lilyjcollins @phoebejtonkin (sic)"

The 'Neon Demon' star was also reportedly spotted wearing the sparkler at a Virgin Australia Melbourne Fashion Festival event in February.

Details of how Andrew proposed and when they plan on tying the knot are yet to be revealed.

Andrew, who is 20 years Bella's senior, has been dating the Australian star for six years.

Prior to his relationship with the brunette beauty, Andrew was engaged to 'Prison Break' star Robin Tunney, however they broke up in 2010.

The engagement may come as a surprise as insiders said previously Bella wanted to find a boyfriend who doesn't work in the movie industry.

Last year when she was single, the source said: "She wants to hook up with a guy who is unrelated to Hollywood in any way.

"She is all ready to start a serious relationship, but she has decided that she would only see normal guys who want to stay away from all the hustle and bustle of Tinsel Town. And she means it! Several of her former boyfriends were from the show business. They were either actors or movie makers and not a single one of her relationship lasted. So now, she wants to give love another shot but this time she is determined to date someone who can bring some normalcy into her life and not date her just because she is famous."