Hilary Duff at National Kidney Foundation of Southern California's 28th Annual Gift of Life Celebration and Award Dinner held at the Warner Brothers Studios. Los Angeles, California - 29.04.07

The 19-year-old split with Good Charlotte frontman Madden last November (06), and he started a relationship with Richie not long after.

Duff tells US magazine Hollywood Life, "I love him, he's a really great person.

"But I broke up with Joel, and when I decided that breaking up was the right decision, I had to think through all the things I was going to have to deal with. One of them was seeing him with someone else.

"It's definitely difficult to see him move on so quickly."

Source: WENN