Los Angeles, Aug 8 (IANS): Actors Kristen Stewart and Robert Pattinson, who have been together for four years, had reportedly been talking about starting a family before Stewart wrecked their plans by having a fling with her married "Snow White and the Huntsman" director Rupert Sanders.

"They had been talking about having a baby together once 'Twilight' ended, which is what makes this so extra-painful. Kristen knew how badly Robert wanted to start a family, and it was a subject that had dominated their conversations in recent months," femalefirst.co.uk quoted a source as saying.

"Robert would be a great father, and having a baby would probably have brought them even closer together," added the source.

Although the couple has not released a statement on the future of their relationship, Stewart, 22, fears there is no way back for them and their baby dreams are over.

"Kristen fears she will never have the chance to get Rob back, and that their baby dreams are now totally shattered. Kristen feels so terrible, this is truly a nightmare for her, but there's nothing she can do to turn back time.

"If Rob takes her back at this point it will be a miracle, but she knows she only has herself to blame," said the source.

She admitted she had cheated on Pattinson, 26, with Rupert after pictures emerged of them kissing in a car and released a statement saying how sorry she was.

Sanders has two children, Skyla, seven, and five-year-old Tennyson, with wife Liberty Ross.