After retweeting a photo of the 26-year-old actress, Carter then wrote, "Don't be that stupid douche that loses the love of your life forever.. Like me..."
He added, "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."
Carter concluded by stating, "That tweet just gave me an anxiety attack."
Well, seeing how Duff recently split from husband Mike Comrie, Carter clearly views the breakup as an opportunity to reunite with his ex.
The two became an item more than a decade ago before Carter famously broke up with Duff amid speculation he had hooked up with Lindsay Lohan.
"I started dating Hilary on my 13th birthday," Carter recalled a while back on The Big Idea With Donny Deutsch. "I was dating her for like a year and a half, and then I just got a little bored, so I went and started getting to know Lindsay, dating Lindsay."
Of course, we all know how that teen love triangle ended up, with all three eventually going their separate ways.
Guess time will tell if Duff will take Carter back this time around.