Ruby Rose has been in a relationship with Australian entertainer Jessica Origliasso from the duo, The Veronicas, for just over a year.
Now, it appears Ruby and her girlfriends twin sister Lisa Origliasso are in a heated argument following yesterdays same-sex marriage postal vote results.
Rose, 31, has tweeted to claim Lisa, 32, had commented that the pair should 'feel lucky they don't get stoned to death like they do in other countries' before deleting the social media post.
'So glad to see Lisa Origliasso screaming in excitement about the yes vote after telling us she thinks we should feel 'lucky' we don't get stoned to death like they do in other countries and to get over it a few months ago,' the actress wrote.
'Really warms my heart,' she added, including the rolling eyes emoji.
Lisa had immediately celebrated the vote on her social media accounts, which saw a majority of Australians pledge their support for marriage equality.
A number of Ruby's 1.33 million Twitter followers blasted her for her rather bold response to such a positive moment.
'It's an emotional day. I'm a human being and need to remind myself not to let the people below try to drag me down,' Ruby wrote after deleting her original tweet.
One Twitter user replied: 'They're only below you because you dragged them down, great choice on a day we should we celebrating togetherness and equality.'
Tension between the ladies appeared to simmer in April this year when Ruby unfollowed Lisa on Twitter, with Jessica doing the same in September.
It appears Lisa does not follow her sister nor Ruby on social media, and hasn't posted a candid photo with her twin in many months.
Lisa, who is engaged to actor Logan Huffman, is yet to comment on Ruby's since-deleted tweet.