When Romeo was talking to his friends, Juliet's nurse came to give Romeo a message about if Romeo wants to marry Juliet. He told the nurse to tell Juliet that he made arrangements about the wedding. He told the nurse it will be in Father Laurence's house
When Juliet received the message, she went to Father Laurence's house where she and Romeo will be secretly married. They both went in the basement of Father Laurence's house and they began saying that they loved each other and they will be together.