Hugh Hefner's widow Crystal Hefner felt like she was "wearing a costume" in the Playboy mansion.

The 37-year-old model/reality TV star was married to the late Playboy boss from 2012 until his death in 2017, and she's put pen to paper to tell all about the years spent as the magazine publisher's lover in her new book 'Only Say Good Things'.

In a new interview, the blonde beauty has admitted she didn't recognise herself in pictures from her time in Hefner's former residence where he hosted his infamous Playboy Playmate parties with A-listers and the Playboy Bunnies.

She began an interview with Us Weekly magazine: "I was in that bubble for a decade."

She went on: "I wasn't one of the three girlfriends on a show.

"We were married; I was there with Hugh until he died."

Crystal had her breast implants removed in 2016.

She admitted: "I look at photos of when I was at the mansion, and it feels like I was wearing a costume."

Crystal recently opened up about undergoing therapy and "deprogramming" after leaving the Playboy mansion, and how it has taken her a long time to move on.

She told the New York Post she underwent hours of therapy and "deprogramming" to get herself back on track.

Crystal said of the new book: "It’s called ‘Only Say Good Things’ because I [had] a conversation with Hef and he let me know: ‘Once I go, when I’m gone, please only say good things about me'.

"I kept that promise for the last five years. After going through a lot of therapy and healing, I realised that I needed to be honest about my time there. The book is about healing from a toxic environment."

Crystal was 21 and Hefner was 81 when they first started dating, and she says it's taken professional help to untangle her complicated feelings about their relationship.

She explained: "It was very, very fast. I think he had a lot of experience with just moving people in [to the mansion] right away. The ‘I love yous’ started pretty quick. I’ve learned all about love bombing since then."

She went on to reveal she wanted to leave Hefner in the later years of their relationship - even calling off their 2011 wedding before eventually tying the knot with him a year later - but she felt too guilty to walk away.

Crystal added: "As he got older, [Hefner] just got more needy and dependent on me ... Towards the end of his life, I felt like I couldn’t leave him. I had to take care of him. It was like, ‘OK, he adores me and he needs me, and he leans on me for so many different reasons and I can’t leave him.’ So I was there till the very end."

Despite the ups and downs, Crystal insisted she was devastated by his death in 2017 and didn't leave her bedroom for two weeks as she mourned his loss.

As well as writing her book, Crystal is planning to launch her own podcast and she's revealed she's back on the dating scene but has yet to find love.

'Only Say Good Things' is set for release in January.