Terminar una relación de un plumazo

[ROBINDESBOIS]

ENGLISH?
Maybe on the spur of the moment.

[pjt33]

"On the spur of the moment" significa "sin haberlo pensado antes". Me parece que "de un plumazo" es algo como "instantáneamente", no "impulsivamente". En tu ejemplo "just like that" sirve:

She ended the relationship just like that. In the morning it was all smiles, and I came home to find my suitcase in the road.

[ROBINDESBOIS]

Thanks Pet.