In order to be healthy you must pull your energy back from a situation when someone is not giving their energy in return.
Energy imbalance is no joke. If you are giving, giving, giving and they are not investing evenly as well then you will find yourself depleted quickly.
This does not mean that you have to pull back completely but just enough to make sure you are not doing yourself a disservice.
This applies to any energy exchange whether it be intimate, work, etc.