Fans jumped to congratulate the happy couple, including many of Luke's Love Island co-stars.
"Congrats brother!!!" the season's runner-up Matt Zukowski penned.
"Congratulations brother!!! Little sad it wasn’t me though," joked Gerard Majda.
"Congrats you little cuties!!" Jessie Wynter exclaimed.
Of course Luke's twin brother shared his own message of celebration on his Instagram Stories by re-posting Luke's post with the caption: "Congrats you two."
Luke and his wife-to-be made their Instagram debut in December 2019 when the Love Island star shared an intimate photo of the two sharing a kiss.
"If your God is money, you will always be poor; But if your God is love, you will always be rich. X" he captioned the snap.
Luke left the villa just a month before after an unsuccessful shot at love with his co-star Cassie Lansdell.
Luke's twin Josh, meanwhile, is one of the two successful couples to emerge from Love Island Australia.
The quiet achievers ended up winning the competition but were surprised as much of the attention throughout the series was on unlikely couple, Adam and Cartier.
"Obviously, Josh and I really didn't think we had any chance of winning because we weren't in the original cast and normally the winners are an original cast member. So when our names were called out we were like 'Oh my god! What's happened?'" Anna explained after their win.
The couple are now living together in Melbourne and despite the challenge of living in lockdown seem more loved-up than ever.