When someone says "I know" in reply to " I love you.
Usually for either people who don't like replying "I love you (too)" in public (or at all), or people just trying to be clever. Has the effect of making a girl want to punch you (as a jerk
) and want to make out with you (as a bad boy
) at the same time.
Taken from " Star Wars
Episode V: The Empire Strikes Back", where Leia reveals to Han that she loves him, and Han replies, "I know."
Girlfriend: "So... I told him I loved him."
Her friend: "What did he say?"
GF: "He ended up pulling a Han Solo"
HF: "NO. WAY."
GF: "Yah. So I punched him on his shoulder."
HF: "And then?"
GF: "We just made out the rest of the movie."