Kelly thinks she works hard to make sure that her relationship with her boyfriend michael is fulfilling and fun. however, lately she has begun to think that michael doesn't appreciate her efforts. according to this relationship might not last.

I believe the answer is: social exchange theory
social exchange theory views that Our society was built on the act of exchange that initiated by a certain members of society that would benefit one another.
The relationship above would most likely to fail because the exchange only benefit one partner and not the other..