Duff told E! it's because she and the former hockey player are still good friends and still love each other.
"We're constantly seen together and people are like, 'What are they doing? Are they back together? Are they not?' We're really good friends and we have so much respect for each other and obviously Luca is our No. 1 priority," she said, speaking of their 2-year-old son.
"I think we got to a point where we were like, we really need to honor happiness and whatever that is and however we need to sort that out or work that out, we're doing that. We love each other so much and we love spending time together. So when you see us out it's not just for Luca, it's because we make plans and we hang out and we don't know what our future looks like right now but we're both doing really good and just figuring out what makes us happy," she added.