The couple ended their marriage last year following allegations that Ashton had been cheating on her with a number of women but after pictures surfaced of the 'Two And A Half Men' actor kissing new love Mila Kunis, Demi, 49,reportedly became hysterical.

A source told RadarOnline: "Demi is devastated that Ashton has moved on so quickly and is dating Mila. She is beyond heartbroken.

"Even though Ashton cheated on her all the time, it was with random girls, it wasn't a relationship like it is with Mila and that is what is killing Demi now.

"Seeing photos of him kissing another woman is too much for her to handle, it's like having her nose rubbed in it time and time again. She kind of knew it was definitely over between them but I think she was still holding out a little hope for a reconciliation -- now he's actually dating someone else she knows that's not going to happen."

Ashton, 34, and 28-year-old Mila have been friends since working on 'That 70s Show' together and their relationship is said to be "like a knife" in Demi's heart.

The source added: "Each time Demi hears about Ashton and Mila it breaks her heart. She really loved him despite the flaws in their marriage and to see him dating someone new, who is so much younger than she is, is like a knife in her heart."