In what episode of glee does Finn say you know said was wrong but that kiss real?

The quote "You know, said was wrong, but that kiss...real" is actually spoken by Rachel Berry, not Finn Hudson, in the Glee episode "The Power of Madonna".

This occurs after Rachel and Finn have a heated argument about their feelings for each other, and Rachel's jealousy over Finn's interest in Santana. In the context of the episode, Rachel is referring to a kiss she shares with Finn during a Madonna-themed performance.