Mais uma opção:
Ditto = The same
Person A: I love you, sweetie!
Person B: Ditto.
Person B resorted to economy of words here. PB didn't (want to) go to the trouble of saying, "I love you too!"
Ju: "Well, Zé, I love this song!"
Zé: "Ditto." (= So do I; same here)