Fast forward to season two when Blake Garvey popped the question to a pre-Home and Away Sam Frost. The relationship may not have had the fairytale ending that Tim and Anna had, but she too was wearing a black frock at that first cocktail party.
Season three saw Sam Wood and Snezana Markoski's heartwarming romance unfold, and what was Snezana wearing when she taught her future husband how to pronounce her name? You guessed it, a black dress.
The most recent Bachelor winner Chelsie McLeod also wore a one-sleeved black dress when she met her short-lived boyfriend Matt Agnew.
Even the season when there wasn't a winner (*cough Honey Badger cough*), last girl standing Brittany Hockley wore a dark, floor-length ballgown when she met Nick Cummins. Ok it was navy blue, but still pretty close.
Of course, there is always an exception to the rule and in this case there are two.
Season four's Alex Nation and season five's Laura Byrne opted out of the unofficial black frock dress code and instead wore green outfits to the first cocktail party. Whilst Alex sparkled in a sequined forest green number when she met 2016 Bachelor Richie Strahan, Laura left Matty J speechless on their first meeting in an olive green two piece.
Since none of Locky's remaining girls wore green when they rocked up at the mansion, we're sticking with this black dress theory.
And if it rings true, Irena will be the last girl standing. We'll have to wait and see what happens.
There have been a few subtle clues that nurse Irena Srbinvoska steals Locky's heart and wins season eight of the show.
Aside from our *totally legit* dress theory and being the betting agencies' number one pick, a former winner has also noticed a sign.
Upon watching this season’s premiere, season seven's Chelsie pointed out a clear change in the show’s music on Irena’s entrance.
"Ooh, winner's music!" she said in an Instagram video before captioning: "Top four surely... that music. She's cute.”