The 19-year-old Australian pop star dated the 20-year-old supermodel on-and-off for two years before they called it quits for good in 2015, and Gigi is now dating former One Direction singer Zayn.
Although Cody once called her his girl, he doesn't harbour any resentment towards her for moving on so quickly.
The model dated Joe Jonas after splitting from Cody and then found love with the Pillowtalk star, who was previously engaged to Little Mix star Perrie Edwards.
"It's just kind of the natural way things go," Cody told ET Online when asked for his thoughts about his former flame's new relationship. "You're going to expect that kind of stuff.
"But I'm always very happy for her and her career and that type of stuff. I know how hard she's always worked to kind of get to the point in the modelling industry that she's at now, and I couldn't be more proud of her. We still talk every now and then. It’s nice."
Cody, who was most recently romantically linked to Aussie model Sasha Ray, is too busy working on new music to be envious of other people's happiness, and he admits his love split has inspired him as a songwriter.
"I've kind of been going a different way, taking a little time for myself just hanging out and keeping it low key, and working on my music," Cody explains of how he got over his break-up. "I'm writing a lot about the development of a growing man.
"Developing your own sort of personal philosophies, ideologies, perspective on the world and everything - just kind of really trying to sort of understand myself. And I think the best kind of works and lyrical content come from your most solitary moments."