Actually, Anthony was in love with his sister, Mary.
But since she was clearly smitten with their first cousin Vincent, he realized of course that she was off limits. All he could do to display his affection was try & keep her sheltered from the family business.
Trying desperately to maintain some sense of heterosexuality, Anthony thought about pursuing his Aunt Connie...but she was just a little too devoted to her brother, Anthony's dad.
Anthony then had no choice but to turn to his other cousin, Tom's son the priest (what was his name again?). An interesting subplot which usually goes unnoticed because there is no indication of it whatsoever in the flm...is that they were lovers all along.
Congrats, Freddie C. You figured out the whole thing.
Apple