Final answer:
Carol ends her relationship with Michael because he superimposed his head onto her ex-husband's body in a family Christmas card, showing a lack of understanding of relationship boundaries.
Step-by-step explanation:
Carol breaks up with Michael because of a socially inappropriate and invasive gesture. Carol ends her relationship with Michael because he superimposed his head onto her ex-husband's body in a family Christmas card, showing a lack of understanding of relationship boundaries.
Michael superimposed his own head onto Carol's ex-husband's body in their family Christmas card. This act demonstrated a lack of boundaries and respect for Carol's past and personal life, which understandably led to her discomfort and decision to end the relationship. Michael's actions likely made Carol feel that he did not understand the proper norms of a relationship, prompting her to break things off.