In Ian McEwan's "Sweet Tooth," the theme of loyalty and sacrifice is explored through the protagonist's conflict between family obligations and romantic relationships. The character gradually transitions into one of the many men who prioritize their new partners over their children, reflecting a societal trend of neglect in favor of personal desires.

This dynamic raises important questions about the impact of such decisions on children's well-being and the moral implications of abandoning familial responsibilities. The narrative critiques the emotional consequences of these choices, highlighting the struggles faced by those caught in the crossfire of love and duty.