Fans cooed over the sweet snap, including expert Mel, but her comment wasn't entirely true.
"OMG you guys this is the cutest! Our first MAFS baby with his own little fashion statement," she penned.
Diehard MAFS fans will know that season one's Zoe Hendrix and Alex Garner welcomed their baby daughter Harper in 2016 and one fan, spotted by the So Dramatic! podcast, pointed this out to Mel in the comments.
However, the relationship expert acknowledged her gaffe replying, "Yes of course, my mistake."
Since Zoe and Alex, who have since broken up, were on the show back in 2015 when Mel wasn't yet an expert, we can see why that happened, though.
Mel, along with expert John Aiken, is returning as an expert for season eight of the controversial social experiment.
However neuropsychotherapist Dr Trisha Stratford has decided to hang up her MAFS hat and issued a statement in September announcing that she was leaving the show.
"After seven seasons of Married At First Sight I have decided to step back from the television series to focus on my writing, research and neuropsychotherapy," Trisha said in a statement to 9Entertainment.
"I've been involved right from the beginning in the challenge of bringing this social experiment to television. The program provides a platform for an ongoing conversation on relationships and I wish the program continued success and hope future participants find everlasting love."
Filling Trisha's shoes will be Puerto Rican sexologist and TV presenter Alessandra Rampolla.
The certified clinical sexologist has worked as a therapist with couples and families for years, and has appeared on numerous TV shows, hosted her own radio show and has written several books on love and relationships.
“I am thrilled to be joining John and Mel in Australia’s biggest social experiment,” Alessandra said in a statement following the announcement that she'd be joining the MAFS family.
“With my particular expertise, I hope to contribute to the complex mix of components that ensure marriages not only work but thrive in the long haul.”
She added: “One of my strongest core beliefs is that sexual expression and compatibility are vital in building, nourishing and maintaining healthy romantic relationships, and it is my pleasure to help guide our participants in balancing this important factor in their brave quest for love.”