Ludwig told Feliciano that he loved him by printing off a list of Italian phrases and Feliciano had to determine which one meant the same thing as the sentence Ludwig gave him, which was a German phrase.
The German sentence:
"Ich liebe dich."
Once Feliciano figured it out, Ludwig looked him in the eye and told him that.
The German potato was then smothered in hugs, kisses, and tears.