Kristen Roupenian, whose short story about a relationship turned sour, Cat Person, set the internet on fire last week, has sold her debut book to a UK publisher for a high five-figure sum, with an auction in the US now understood to be topping $1m (£748,000).

Published in the New Yorker, which said the response to the story had been “record-breaking”, Roupenian’s Cat Person recounts student Margot’s relationship with the older Robert. Initially conducted through text messages, it eventually becomes physical – “It was a terrible kiss, shockingly bad; Margot had trouble believing that a grown man could possibly be so bad at kissing” – before Margot withdraws and Robert shows his true colours.

The story was the first Roupenian had published in the New Yorker. In an interview with the magazine, the author said that she had only “really committed” to writing fiction in the past five years, also mentioning that she was “putting the finishing touches on a short-story collection”.

That collection, You Know You Want This, has now sold to UK publisher Jonathan Cape, with an auction understood to be under way in the US, where 11 bidders have sent the price tag over $1m.

“I was submitted the collection on Tuesday. By Wednesday, I had bought the book. She’s the real deal,” said Michal Shavit at Cape. “Cat Person captured the public imagination to become a phenomenon. You see that so rarely in literary fiction. It’s an extraordinary story of human relationships and the sexual dynamics between a man and a woman, the power plays within that. It doesn’t just play into the #metoo thing – she just writes very honestly and truthfully about the human experience.”

Shavit added that “not many people have written about the experience of modern-day dating in the way she has”.

But the stories in the collection, said the editor, are not only about relationships. “They’re dark, they’re funny, they’re irreverent, they’re treading boundaries, and they’re very different to one another,” she said. “They’re occupying a similar space in the imagination, but they’re not all about the relationships between men and women … I genuinely think she’s a brilliant writer.”