Tugging

What happens if you have two things—or two facets of a character's personality—that are equally important to the protagonist but conflict with each other?

We could use the tug between a character's work and his family—and a character who loves both things equally. Suddenly we increase his work demands and his family needs simultaneously. How will he respond? What kinds of choices will he make and how will it change the plot? Maybe he misses his shot at promotion when he spends more...