Answer:
The answer is "to respect the recipient's right to end the relationship."
Step-by-step explanation:
The interjection of the phrase "if ever" in the first line ("Then hate me when thou wilt; if ever, now;") suggests that the speaker recognizes the possibility that the recipient may eventually come to hate him. The speaker urges the recipient to end the relationship now if he or she feels inclined to do so, rather than waiting until a later time when the speaker has become more invested in the relationship. This emphasis on the importance of the recipient's agency and right to end the relationship suggests that the speaker wants the recipient to feel free to make their own decisions about the relationship.