Creature's Knowledge of Marriage?

In Frankenstein by Mary Shelley, the creature decides to kill Elizabeth, on Victor's wedding night. But how did the creature know that Victor was going to be married: " 'I will be with you on your wedding night' " (Shelley, 123)? The creature has only had human contact with the DeLacey family and Victor. The DeLacey encounter was brief and had no connection with Victor. Victor's first spoken interaction with the creature was upon an isolated mountain. There, they discuss the creature's history and demand. There was no mention of Victor's future planned marriage. After that, they part ways and will not see each other until he threatens to kill Elizabeth. Furthermore, the creature believed William to be Victor's son. If William was Victor's son, then Victor should have already been married. There is no information explaining how the creature understands that Victor will be married.