For decades, the name Larry Flynt has been synonymous with the porn industry. It was the “Hustler” publisher who challenged obscenity laws and promoted efforts to expand freedom of expression under the 1st Amendment, immortalized in the Milos Forman film “The People vs. Larry Flynt.”

But expression apparently goes only so far.

Now, Larry Flynt is suing his nephews — Jimmy Flynt II and Dustin Flynt — in U.S. District Court in Los Angeles, alleging trademark infringement because they used the name “Flynt Media Corporation” in seeking to distribute their own adult films.

In the lawsuit, Flynt notes that the Flynt name is connected to Hustler magazine, which has been a registered trademark since the early 1970s. “Hustler” has been used in connection with related publications, adult-themed video and DVD releases, various websites and adult-content stores.

The Flynt “name and mark has become famous, has acquired secondary meaning to the public,” the suit states. It adds that the “defendants have blurred and tarnished the distinctive quality and good will of the Flynt name and mark in the adult entertainment industry.”

The nephews worked for Flynt before he fired them a year ago. That led to their venture, a line of their own adult-themed movies that go by titles such as “Positive Exposure” and “Sex at Your Service.”

“It’s my brother and my turn to be successful in this business,” said Dustin Flynt, who noted that he jumped into the industry out of high school and worked his way to the top. “The fact of the matter is my name is Flynt. If I can’t use my name to do business, then what kind of society, what kind of world is that?”

But their uncle didn’t mince words about his take on the films, calling them “inferior products” and “knock off goods” in the suit.