Alec Baldwin's impersonation of Donald Trump on SNL prompted brother Stephen to call it "not funny". Now, Billy Baldwin has taken a shot at his Republican brother.
"If my father were alive today (a veteran) He would be ashamed & disgusted of media biased and manipulation by people like @andersoncooper," Stephen, 50, tweeted.
It sparked a quick response from older brother, Billy, 53.
"If our father were alive today ... he'd smack you in the side of the head for supporting Donald Trump," he replied.
He later deleted the tweet.
The exchange, made earlier this month, is only now going viral after Stephen criticised his brother Alec, 58, for his critically-acclaimed turn as Trump on Saturday Night Live.
"I don't want to be a party pooper here, but I don't think it's very funny," he told CBS News. "He's got the voice down very well [but] I think it's getting a little nasty right now."
Those comments resulted in another tweet from Billy.
"Brother Stephen thinks Alec's impersonation of Trump is "not funny" and that Trump 'dominated' the debate last night," he wrote. "Just proves the alt universe that many Trump supporters live in."
In the latest episode of SNL Alec's Trump also took a swipe at his brother.
"I've got Sarah Palin (supporting me), I've got Chachi (Scott Baio) and I've even got the best Baldwin brother - Stephen Baldwin," he said.
Stephen, the father of model Hailey Baldwin, has not commented on Billy's tweets.
However, overnight Billy was forced to take to Twitter again to let the world knows that he loves his brother, even if he doesn't care for his politics.
"BTW ... love Stephen. Just KNOW our father would never support the politics of a man like Donald Trump ... EVER," he wrote.