expression, ichidan verb
lead someone on; raise someone's hopes; give someone false expectations
Used when someone's words or actions make another person expect something (often romantic interest or a favorable outcome) that may not be fulfilled. Often carries a negative nuance of being misleading or unfair.
彼は彼女に気を持たせるようなことを言った。
He said things that led her on.
If you answer like that, you'll raise the other person's hopes.