Who is The Ravannos from Tortilla Flat and what is their importance?

A childhood friend of Jesus Maria, Petey Ravanno hangs himself when cruelly rejected by the beautiful Gracie Montez, but his father, Old Pete, cuts him down in time. Gracie marries Petey, reforms her ways, but their moving into a separate house leaves Old Pete lonely. He falls in love with Gracie's more-beautiful younger sister, 'Tonia, and in desperation tries Petey's ploy to win her over. He times the hanging perfectly for the opening of the gas station where he works, but the wind blows the door shut and no one finds his body for hours. Everyone laughs over his tragic end, and Petey begins dallying with 'Tonia.