Rep. Katie Hill admitted this week that the relationship she...

Freshman California Congresswoman Katie Hill is starring in a ­lurid, snowballing sex scandal — a very public saga complete with leaked nude snapshots, alleged bong use and a questionable tattoo.

Most seriously, Hill is now the subject of a career-threatening House ethics investigation into allegations she bedded not one, but two of her young legislative staffers — one of them male, the other female.

It has been just under a year since the 32-year-old Democrat catapulted onto Capitol Hill, earning accolades as an openly bisexual progressive who flipped a longstanding red district and quickly rose to vice chair of the powerful House Oversight Committee.

Now at least two political rivals are calling for her resignation.

“It could have put our nation at risk due to her heightened potential to be blackmailed,” tweeted Angela Underwood Jacobs, a Republican rival for Hill’s 25th District seat in suburban LA.

“She needs to resign,” agreed another GOP rival, Mike Garcia.

The recriminations started last Friday, when the conservative blog RedState reported accusations that Hill had twice violated House rules against sex with subordinates.

Hill has been “sleeping with her [male] finance director for the past year at least,” her estranged husband, Kenny Heslep, posted to his now-deleted Facebook account earlier this year, in a reference to legislative staffer Graham Kelly, RedState reported.

“I didn’t file for divorce bc she was bi!” the husband wrote of Hill in ­another Facebook post.

“I just didn’t know she opened our relationship.”

Hill, meanwhile, has strenuously denied an affair with Kelly.

“Allegations that I have been involved in a relationship with Mr. Kelly are absolutely false,” she said in a press statement.

“I am saddened that the deeply personal matter of my divorce has been brought into public view and the vindictive claims of my ex have now involved the lives and reputations of unrelated parties.

Heslep apparently had no problem with his wife’s interest in the first staffer, identified by the Daily Mail on Thursday as 24-year-old campaign worker Morgan Desjardins of Santa Clarita, California.

That’s because he was a willing participant, RedState and the Mail reported.

For more than a year, Heslep, Hill and Desjardins were a committed “throuple,” a polyamorous threesome, the two outlets reported, allegations substantiated through a series of leaked photographs and text messages.

Both online news stories were decorated with photos of Hill, nude, brushing Desjardins’ hair.

Other photos showed Hill and Desjardin canoodling during a vacation in Alaska.

But life in Washington, DC, can put a strain on many relationships.

Hill called it off in May, four months after the move to DC.

Desjardins was despondent, according to texts leaked to RedState.

“I still care about you,” she wrote in one of the leaked texts.

“But I think I need a little more time to “move on” before we can be friends … Like please understand it’s not because I hate you it’s just because it hurts too much to think about you at this point in time.”

Hill had slammed the “throuple” accounts as a “smear campaign.”

“Intimate photos of me and another individual were published by Republican operatives on the internet without my consent,” Hill seethed in response.

“I have notified Capitol Hill police who are investigating the situation,” she wrote in a press statement after RedState broke the story.

She has since admitted the “throupling,” which began shortly after she hired Desjardins to work on her congressional campaign in late 2017, was “inappropriate.”

“I know that even a consensual relationship with a subordinate is inappropriate, but I still allowed it to happen despite my better judgment,” Hill said in a statement. “For that, I apologize. I wish nothing but the best for her and hope everyone respects her privacy in this difficult time.”

On Thursday came a fresh round of revelations.

The Daily Mail published new photos showing Hill holding a smoking bong and wearing nothing but what appeared to be a tattoo that looked like an Iron Cross on her bikini area.

Hill did not respond to questions about the photo or explain exactly what the tattoo was.

Iron Crosses are sometimes used as symbols by neo-Nazis as they are similar to a German military medal handed out until the end of World War II, according to the Anti-Defamation League. The group cautioned, however, that such crosses are not always racist and are often used innocently by other groups, such as bikers and skaters.

Late Thursday, Hill’s lawyers sent a cease-and-desist letter to the Daily Mail demanding that it take the racy image down as it was an “invasion of privacy” — and denying the tattoo was linked to bigotry.

“The claim that Representative Hill has Nazi imagery on her body in the form of a tattoo is false and defamatory,” her attorneys wrote, according to the Huffington Post.

Heslep also did not respond to requests from The Post for comment.

The Mail hinted that yet more “intimate” photographs were out there — posted somewhere online by Heslep “under a thread called ‘WouldYouF**kMyWife.’ ”

Additional reporting by Laura Italiano