The Italian businessman who unwittingly plunked down $8.3 million on a fake Mark Rothko painting said Wednesday that the gallery director he’s now suing was “very aggressive” in selling him the work in 2004.

“She was very, very vocal and very aggressive about it,” Domenico De Sole said of Knoedler & Co. director Ann Freedman in the Manhattan federal-court trial.

De Sole said he first suspected the Rothko was fake when his wife alerted him to an article about a forged Jackson Pollock sold by the gallery.