Matthew McConaughey's abusive father broke his mother's middle finger four times during their violent arguments.
The Interstellar actor shared a photo of his mother Kay's bent middle finger as proof of his father James' abuse in in his new memoir Greenlights, revealing rage was how his parents "communicated" and showed love in their toxic relationship.
Oscar-winner Matthew, 50, said of one particularly violent row between the two was sparked by Jim asking for more potatoes at dinner, with the actor recalling: "'Sure you want more potatoes, FAT MAN?' she barked. That was it. BOOM!"
"Dad flipped the dining table into the ceiling, got up and began to stalk Mom," he continued, explaining he and his older brothers Michael and Patrick "knew the deal" and watched their mum run to the telephone in the kitchen to call the police.
However, before cops arrived she ended up hitting James in the face with the receiver, as the couple then "circled each other" while Matthew's mother grabbed a 12-inch chef's knife to defend herself against her husband, who was now threatening to bash her with a glass bottle of Heinz ketchup.
According to the star, the couple suddenly stopped brandishing their weapons and dropped to the kitchen floor "to make love," explaining: "This is how my parents communicated. This is why my mom and dad were married three times and divorced twice – to each other.
"This is why my dad broke mom's middle finger to get it out of his face four separate times. This is how my mom and dad loved each other."
Dallas Buyers Club star Matthew also admitted ex-American football player James gave his kids beatings for misbehaving, revealing in the new tome his first "ass whupping" came simply for answering to the name "Matt" while at kindergarten, with his mother screaming: "You weren't named after a doormat!"
He was also reprimanded for lying about paying a bill at Pizza Hut that he and his pal walked out on, and for "saying 'I hate you' to my brother" and "I can't" on two separate occasions.
James died in 1992, aged 63, before Matthew became famous, with the star previously revealing his father had died while having sex with Kay.
