"Birthday boy," she simply wrote in the caption, alongside love-themed emojis.
This cute post comes three days after the two were spotted in a video filmed at Sydney Airport on November 21 and posted on news.com.au – where The Bachelorette couple revealed they are still together.
"She brushed me, didn't she brush me?" Stu joked when asked about their relationship status.
"So this is a fully fledged relationship, there's no problems here?" the cameraman asked.
To which Laundy responded, "I wouldn't waste my time coming to the airport if it wasn't!"
Sophie then chimed in, "It's all good."
Sophie also opened up about finding love with Stu to Who.
"I was scared going in, but I knew the success rate, so that’s why I did it. I’d choose no one at the end if I wanted to — I wouldn’t be able to fake it. I couldn’t."