Hilary Duff wants ex-boyfriend Aaron Carter to move on from their past relationship.

"Don't be that stupid douche that loses the love of your life forever.. Like me...," Carter, 26, wrote on Twitter in March after retweeting a photo of the 27-year-old singer-actress.

When a fan asked him if he was referring to Hilary, the "I'm All About You" hitmaker replied, "Sure am!" adding, "I'll spend the rest of my life trying to better myself to get back to her. I don't care what ANY of you think."  

Duff has previously addressed Carter's affectionate tweets about her several times, but in a new interview with  Elle Canada, the "Chasing the Sun" singer said that it is time for the Tampa, Florida-born recording artist to move on.

"Oh, God, I feel so uncomfortable right now," Duff said after the interviewer brought up the topic. "I don't know what to say. The more I talk about it, the more I think he's going to talk about it. We were like 13 and 14.... I don't want him to be hurt-I don't want to make anyone feel like that-but it's time to move on. I have."

"What's funny, though, is that those feelings-I'm not talking about him but young love in general-feel so real," added Duff, who dated the pop singer on and off between 2001 and 2003. "You always kind of think about it. When you're dating, you can never quite get that excitement again, because you're never that age again."

During her appearance on Bravo's "Watch What Happens Live" last month, host Andy Cohen also asked the "Lizzie McGuire" star how she felt to have Carter "declaring his love" for her, according to E! News.

Duff responded, "It's...ugh! I don't know. I don't know what to say about it! It was so many years ago. I literally haven't seen him in...so, it's uncomfortable."

"He's just feeling you on Twitter publicly," Cohen said. Duff replied, "It's nice to be felt," adding that Carter  "was very sweet" when they were together.

But two weeks before Duff's appearance on "Watch What Happens Live," Carter told WENN that he would now stop talking about Duff on Twitter. "If I'm too open about how I feel then people wanna nag and pick and poke at me," he said. "I don't know Hilary either. She don't know me and I don't know her. I just need to shut up now about it. I think it's time."

"She's got a kid and she's married and I'm not trying to be that dude," he added. "That's not my intention. Hilary will always hold a very special place in my heart."

Duff and the 34-year-old retired NHL player Mike Comrie tied the knot in August 2010 in Santa Barbara, Calif. In March 2012, the couple welcomed their son Luca. But in January this year, the two announced that they had separated but would continue to co-parent their son.