From Chapter 21: What does Josie have in common with John Barton? Why does she see Macbeth with him? How does this cause tension between Jacob cute and Josie?

Josie and John have both been looking forward to Macbeth. She goes to see Macbeth with John because they'd previously arranged to the movies, and also because she doesn't think that John will be interested. This causes tension because Jacob (and his friends) believe that Josie and Jacob are dating. Jacob is embarrassed.