It takes two to tango but apparently just one after-party to ruin a reputation.

A Seattle suburban resident and tango enthusiast alleges that a gin-infused late-night event at a California Airbnb with other dance aficionados resulted in him being ostracized after one attendee accused him of tampering with the drinks.

According to a lawsuit, Eduard Koller attended a small gathering following the March 2023 Southern California Tango Festival, bringing along tequila and a “gin-based cocktail.”

The party broke up without incident and Koller, 55, took an Uber back to his hotel along with four of his party guests.

However, a year later, Koller asserts he was excluded from a tango marathon in Massachusetts because the co-organizer suspected he had behaved “inappropriately,” as stated in his filings with the Manhattan Supreme Court.

James Oh allegedly told the Redmond, Wash. man only that he’d received “multiple credible claims of inappropriate and harmful behaviors by you. And I’m not comfortable letting you be part of any event I’m organizing or co-organizing,” according to the litigation.

Koller later learned Upper East Side psychologist Tehela Nimroody had accused him of tampering with her beverage during the California after-party, he said in legal papers.

The pair were not alone during the party in question and “did not share any other type of relationship or interactions” aside from meeting at three tango events between 2022 and 2024, Koller claimed.

Nimroody allegedly ignored a Facebook message Koller sent seeking to clarify her claim, he noted.

Koller is seeking unspecified damages and wants a court order barring Oh and Nimroody from posting any “defamatory and injurious content” about him.

Oh declined comment on the litigation. Nimroody did not respond to messages.