Continual lack of attention
Jack in his letter, admitted that the week before, Laura didn’t notice that he had a new haircut and wearing a new pair of silk boxers. He felt unnoticed and hated the lack of attention from Laura.
No Spark
Jack continued to air his grievances on his letter saying that Laura when she comes home usually just eats her dinner in two minutes, watches her favorite soap shows, and just goes on straight to bed. He constantly wonders why Laura doesn’t tell him that she loves him anymore. These were some of the reasons why he wanted to break off the marriage.