As well as the bikini picture, Martha posted a sultry snap to her Instagram account which showed her about to kiss Michael as they lounged at Melbourne's Royal Botanic Gardens.
She captioned the candid pic: "Pretty lucky really."
Meanwhile, Michael also shared a snap of the couple laying in the sunshine together in the park.
The ex-teacher seemed to ridicule rumours of their break up in his caption.
"Let her off the leash for a minute, now she’s back," he wrote.
Fans of the couple became concerned last week and began asking questions after Martha shared a shared a video of herself in a bikini last Thursday.
"Where's Michael?" asked one person, but Martha did not respond.
Another concerned fan wrote: "I hope you and Michael are still together, you have so much fun."