Here is extract 1 from Joseph Fletcher’s Situation Ethics. Try paraphrasing what he says in your own words, using as few words as possible.
Situation Ethics goes part of the way with Natural Law, by accepting reason as the instrument of moral judgment, while rejecting the notion that the good is "given" in the nature of things, objectively. It goes part of the way with Scriptural law by accepting revelation as the source of the norm while rejecting all "revealed" norms or laws but the one command—to love God in the neighbour. The situationist follows a moral law or violates it according to love's need.