It's supposed to be "Je suis tombé amoureux de toi." when you're more intimate with the person or you know them a little better (such as being officially friends or something). ^.- "Vous" is impersonal and should be used on people you consider like a stranger. Or someone who you're trying to be polite with.
Also, no one I know of uses "La barbe" when expressing annoyance. X) You can, as it's a totally valid and safe way to do so, but we French people tend to curse more than that.
@kurisu
I was thinking but since he confirmed himself he's french, his name as a boy should be written as "Lucas" which is the common spelling in France (I do think Luca exists too, but not much for Luka).
@phil777
I wonder since when I heard the word "la barbe" to express the annoyance.
It's like "sacrebleu" I've saw that somewhere but doesn't fit the context