Bobby Lee is defending a controversial story he's repeated over the years about traveling to Tijuana for sex and paying for an underage prostitute -- sordid, for sure, but he says it's also total fiction.
The comedian's recently come under fire on social media due to resurfaced clips of the Tijuana tale ... where the story goes Bobby went to "hooker alley" and picked out a young prostitute who seemed shy.
There are different versions of the story where the prostitute's age differs, including one where Bobby says the prostitute looked like then-13-year-old Natalie Portman in "The Professional" ... but the stories all end with him having sex with the young woman in a cheap hotel room.
Bobby is finally responding to the backlash in the latest episode of his "TigerBelly" podcast ... where he says, "At the end of the day it's not real and I didn't do anything."
The way Bobby explains things ... he first told the joke on "Opie and Anthony," the shock jock radio show from back in the day -- and he says the story was actually a combination of "a couple awful dark jokes."
Bobby understands the current uproar, but he says back when he first told the Tijuana story, "it was encouraged to say crazy stuff without thinking about it" ... and he says "when I listen back to it now it puts a chill down my spine."
He says his views changed with society and now he feels guilt over the story, which he describes as "terrible" and "stupid."