Duff and Koma, 30, were romantically linked in January, displaying plenty of PDA in the following months and vacationing together in Costa Rica. ET then learned in April that the two had called it quits a month prior.
In July, the former Disney star was spotted cozying up with businessman Ely Sandvik. The fling appeared to have been short-lived and it wasn't long before she was spending time with Koma again.
In October, Koma shared a throwback pic on Instagram of him and Duff lovingly gazing at each other. Later that month, Duff also shared a cute pic of the pair.
Meanwhile, she continues to co-parent with her ex-husband, Mike Comrie, whom she recently enjoyed a relaxing beach day with, along with their 5-year-old son, Luca. Check it out: