Australian viewers saw Vanessa accept a marriage proposal from Rhys after giving birth to Patrick in the 2012 season finale, leaving her baby's father Lucas Fitzgerald (Scott Major) jealous and heartbroken.
However, with Patrick's health her number one concern in upcoming episodes, Vanessa calls things off with Rhys and pledges to focus all of her attention on her son.
Alin Sumarwata, who plays Vanessa, told TV Week: "It's sad. Rhys is doing everything he can to be there for Vanessa and support her, but for some reason, everything he does just pushes them further apart. They just can't seem to connect.
"Vanessa also feels torn between Rhys and Lucas, who is now united with her in their concern for Patrick. But breaking off the engagement is heartbreaking for Vanessa."
On Patrick's health scare, she said: "The diagnosis tears her and Lucas's lives apart, and it comes so out of the blue."
Rhys isn't prepared to let Vanessa go so easily, but whether he can win her back remains to be seen.
Ben Barber, who recently finished filming in the role of Rhys, added: "Everything is now on the line in terms of Rhys and Vanessa's relationship."
Neighbours airs these scenes next week on Eleven in Australia and in February on Channel 5 in the UK.