The Expendables star Terry Crews and his brother beat up their violent father when a family reunion turned nasty after a fight.

The actor details the altercation in his new book Manhood, revealing he begged his heavy-drinking father not to ruin a vacation - because his grandchildren would be there.

But when Crews, Sr. lost his cool and knocked out one of his wife's teeth, the movie star stepped in.

He tells Access Hollywood Live, "I dreamed about the day I would be (a) grown man and I could get my father back... I wanted revenge, couldn't wait for it and the time came and I did it... me and my brother beat him up for what he did to my mother.

"It was horrible. I did not feel one bit of freedom, one bit of 'now things are better'. I felt worse, because now I was just like him... I had to forgive him, because forgiveness allows me to not be a victim... Once I forgave him, I was free."