Joss Whedon's ex-wife has accused him of having multiple affairs.

Kai Cole - who separated from the 53-year-old filmmaker five years ago, though the end of their 16-year marriage was only made public this year - slammed the 'Avengers' director for being unfaithful ''multiple'' times during their marriage and claimed he's a hypocrite for ''preaching feminist ideals''.

She claimed: ''He hid multiple affairs and a number of inappropriate emotional ones that he had with his actresses, co-workers, fans and friends, while he stayed married to me...

''Despite understanding, on some level, that what he was doing was wrong, he never conceded the hypocrisy of being out in the world preaching feminist ideals, while at the same time, taking away my right to make choices for my life and my body based on the truth.''

''He deceived me for 15 years, so he could have everything he wanted. I believed, everyone believed, that he was one of the good guys, committed to fighting for women's rights, committed to our marriage, and to the women he worked with.

''But I now see how he used his relationship with me as a shield, both during and after our marriage, so no one would question his relationships with other women or scrutinise his writing as anything other than feminist.''

And Kai claimed the breakdown of their relationship left her suffering post-traumatic stress disorder (PTSD) and she's only now putting her life back together.

She wrote: ''He said, after he left, he understood: 'It's not just like I killed you, but that I'd done it subtly, over years. That I'd been poisoning you. Chipping away at you.'

''He made me doubt my own instincts and watched me move further away from my personal values and social mores, trying to connect with him, never telling me it was impossible.

''By the time he finally confessed the truth, 15 years after his first affair on the set of 'Buffy', I was broken. My brain could not fit my experience of our life together, through the new lens of his deceit.

''My entire reality changed overnight, and I went from being a strong, confident woman, to a confused, frightened mess. I was eventually diagnosed with Complex PTSD and for the last five years, I have worked hard to make sense of everything that happened and find my balance again.

''It has not been easy, because even though in my personal life I have been completely open about what happened, publicly people only know his superficial presentation of us: him as the lovable geek-feminist and me in the background, as his wife and supporter.

''We're finally divorced; I'm doing architecture again, and slowly getting my life and self-esteem back''

A spokesperson for the director said he wouldn't be commenting on Kai's account because it wouldn't be fair to their two children.

They said: ''While this account includes inaccuracies and misrepresentations which can be harmful to their family, Joss is not commenting, out of concern for his children and out of respect for his ex-wife.''