It's a "he said, he said" situation between Mötley Crüe rocker Tommy Lee and his 21-year-old son Brandon Lee, one of two sons Tommy had with ex-wife Pamela Anderson. Tommy claims Brandon sucker-punched him, but Brandon claims he only hit Tommy because Tommy lunged at him. And from thousands of miles away, Pam is chiming in, siding with her son and saying her ex is a "disaster." Here's everything you need to know about this drama…

Tommy and Brandon's fight went down on March 5. Around 10:45 that night, police arrived at Tommy's home in Calabasas, CA, and took a report but made no arrests. Tommy was briefly hospitalized for a reported concussion.

The following day, Tommy posted an Instagram photo of his swollen lip and blamed his son. "My heart is broken," he wrote in the caption. "You can give your kids everything they could ever want in their entire lives, and they can still turn against you."

Just hours before the altercation, though, Tommy criticized Pam for talking about his alleged history of abuse during an interview. "Think she'd find something new to discuss instead of rehashing old s–t," he tweeted. "But I guess she has nothing else going on [and] needs attention. Signed, 'The Abuser' (who she texts everyday [and] asks for me back)."

Family sources told TMZ that Brandon has been living with Tommy part-time to help his father with alcohol issues and that the tweet is what caused their argument that night. According to these insiders, Brandon claims Tommy was drunk and lunged at him during the conversation and he punched Tommy out of self-defense.

Tommy gave an alternate version of the events, tweeting, "My fiancée and I were in bed when my son busted into the room and assaulted me. I asked him to leave the house and he knocked me unconscious. He ran away from the police. That's the truth."

Sources close to the 55-year-old corroborate that story, telling TMZ Brandon burst into Tommy's room — raging about photos of Pam that Tommy was posting — and when Tommy tried to kick him out of the house, Brandon knocked him unconscious. Tommy had blood coming out of his mouth, these sources say, and fiancée Brittany Furlan actually thought he was dead.

The site later released Brittany's 911 call. She phoned the dispatcher while Tommy was unconscious, saying she had locked herself and Tommy in their bedroom. "My stepson has guns in his room, and that's why I'm freaked out," she explained. She also said Tommy and Brandon were fighting about "ugly" Pamela Anderson photos Tommy was posting.

TMZ also says Tommy initially offered to withdraw the police report but changed his mind when Brandon claimed alcohol was a factor in the fight. Now he wants to press criminal charges and get a restraining order, the site says.

Meanwhile, Pamela released a lengthy statement from France, saying she feels this fallout between Tommy and his son means "justice is at work."

She writes: "I have complete faith in Brandon and his team to resolve this unfortunate and sad situation regarding his father. I pray Tommy gets the help he needs. His actions are desperate and humiliating. He is a disaster spinning out of control. And he is not acting like a father …

"Nobody understands the lifetime of disappointment this man has brought our family. Consistently the centre of sadness, drama, and confusion. Jealous of his son's talent and beauty from the day they were born. He is sick. The definition of narcissist/sociopath. His fiancée keeps him drunk. This is what he wants, someone to behave badly with. It's terrible …

"[Brandon] punched him in the nose for all of us who he has hurt. Now Tommy feels humiliated and is attempting to destroy his own so. This is the Devil. This is the disease of alcoholism."

pamela anderson getty images

Shortly afterward, Tommy released his own statement, saying he's not an alcoholic and Brandon was the instigator: "All I wanted from my son was an apology. And my heart is so broken that he would lie about the whole situation. He came in the room angry about my response to Pamela's relentless press about our old relationship, with his dukes up, telling me to get up and fight him. When I stood up he pushed me into a wall. I didn't want to hit my son. I never have, and I never will. If I wanted to clock him, I would have knocked him on his ass. He had no problem knocking me out. I asked him to leave, and he spun around and sucker-punched me. Knocked me unconscious."

More as this story develops. Because you know this family drama isn't close to being finished!