While I found Faulkland to be funny in Act II, I found him to be completely unreasonable in Act III. He even acknowledges this: "to this one subject, whom I think I love beyond my life, I am ever ungenerously fretful and madly capricious! I am conscious of it - yet I cannot correct myself!"

Faulkland wants Julia to love him because she's been struck by the love god - not because of his character or his looks or because her father arranged the betrothal or because he saved her life. He is a complete pill, and I don't blame Julia for being mad and washing her hands of him. In fact, I'm wondering what she sees in him at all.