Singer Jessica Simpson, who was married to Nick Lachey, has revealed in her memoir that she was saddened when she heard that he had moved on too soon after they parted ways.

The two got hitched in 2002 and split in 2006, after which he started his relationship with Vanessa Minnillo, to whom he is now married since 2011.

"So, Nick, you're with another already? Seems that you forgot the love you spoke to me. I'm saddened beyond belief. Alone in the dark, with no one to call my own," she wrote in her memoir, "Open Book" which she shared with Entertainment Tonight, reports femalefirst.co.uk.

"Nick loved the fact I was so strong in my faith and that I had this wide-eyed innocent approach to life. When he proposed in 2002, I said yes," she added.

"We meant a lot to each other and we always will. I want to be very respectful because I married him for a reason and we were together for seven years for a reason. He has a family now and I would never say anything to disrespect that," she said.

Lachey started dating Minnillo less than a year after his split with Simpson. They have three kids together -- Camden (eight), Brooklyn (six), and Phoenix (four).