“Seinfeld.” (NBC)

The characters on "Seinfeld" could have really used the level-headed advice that Amy Dickinson offers in her "Ask Amy" column. And now, they're getting some.

A person writing under the name "Feeling Foolish" asked her how to handle a situation involving a "famous local sports figure" he met in his gym locker room, who then goes on to date his ex-girlfriend.

Yes, this is basically the plot of Seinfeld's "The Boyfriend" (parts one and two), starring former baseball star Keith Hernandez.

Tribune Media Services pulled the letter on Friday, editor Tracy Clark told The Post. "It was reminiscent of a Seinfeld episode," she said.

The company substituted in another letter but not before numerous publications printed the Seinfeld plot.

"Every once in awhile, I get punked by a villainous, fun-loving reader," Dickinson wrote on her site Monday.

She added: "Honestly, I can't believe I missed this one, because I have absorbed enough Seinfeld episodes to power a parallel universe of columns based only on Seinfeld plotlines."

Here's the query:

Dear Amy: I recently ran into a famous local sports figure at my gym.

I didn't want to bother him, but much to my surprise he approached me. Turns out he knew me from my profession. He asked if I wanted to go out for coffee, and we exchanged numbers. A few days later we had coffee, and I thought it was pretty cool that he considered us friends.

Then everything changed. He told me he was interested in taking out a woman we ran into. She is my ex-girlfriend and we've remained good friends. He asked me a couple of times if I wouldn't mind if he asked her out. I reluctantly said no. I made plans with him, and then after talking to my ex I found out that he ditched our plans to go out with her.

The next day he called me and asked if I could help him move some furniture. I barely know the guy, next thing he will be asking me to drive him to the airport. Two friends of mine warned me not to trust this guy. What's the deal — am I being too rash or should I dump the guy as a friend? — Feeling Foolish

And here is Amy's response:

Dear Foolish: The good news here is that you won't have to dump the guy as a friend because he is not a friend. He's an opportunist who just keeps asking you for stuff. I suspect that when you turn down his generous offer to let you move furniture for him, you'll likely never hear from him again.

Did you hear that? Keith Hernandez is "an opportunist." But Hernandez, who has said he makes $3,000 a year in royalties from his Seinfeld appearances, did show up again during the season finale.

Ask Amy has been trolled in a similar manner before. Last year, someone wrote in describing the plot of the movie "The Room." Again, she offered measured advice and wrote that the behavior exhibited in the fake letter was the "very essence of dysfunction." True!

On Monday, Dickinson wrote: "I have some affection for these episodes because I often think that if I didn't actually have a job, punking advice columnists is exactly what I would do with my time. But alas I do have a job and so I am left with the task of sharing my humiliation, as well as trying to enjoy readers' reactions."

This post has been updated.