According to Jim Recap: Plot Twist
When Cheryl's (and Andy's and Dana's) mom declares that she has space in the family burial plot, Jim is ready to revolt. The scary thing is that he isn't quite sure why, he just knows that he doesn't want to be tied to the family in death like he is in life. So he makes Cheryl stand up to his mom (played by Kathleen Noone).
None of them want to stand up to her, but eventually Cheryl does - and when she does, Jim promptly decides, during a lunchtime game of catch with Andy in the cemetary as he's enjoying their new personal plot, that he will be buried next to his hero, Bears great Bronco Nagurski, who he feels intercepted his pass to Andy (in reality, it was just a girly throw). When Cheryl finds out that he's moved his plot to be next to Bronco, she's not happy.
Jim just shrugs it off like he does so many other things, until he has a visit one night from Bronco and realizes that he has made a mistake - so he runs to Cheryl, who his having a sleepover with the other girls at Andy's house, and promptly wakes her up to beg forgiveness - and ask her mom to take them back in the family plot (which she does).
