Pregnant actress Tori Spelling has launched another attack on her mother in her new book, claiming she cheated on her dying dad.

The former Beverly Hills, 90210 star and her mother Candi fell out over TV mogul Aaron Spelling’s will, but recently reconciled after the actress gave birth to her first child last year (07).

But now, their relationship is set to be tested again by revelations in Tori’s new book sTori Telling, in which she claims her mother had an affair while her father was dying.

She says, "I feel that at this point it’s all out there and it’s the truth. So what can they say now?"

But, despite the past and the revelations in the new book, Tori insists she and her mother are on good terms.

She adds, "It’s fine… She’s a great grandmother and, at this point in my life, that’s all I can ask for… that she has a relationship with my son, a relationship with my future child and that bonds us in a way."