There are many ways to explain the meaning of the tittle. From the lecture, the disappointment can be defined as the sexual dysfunction that causes woman’s imperfect enjoyment. However, in my point of view, it means her disappointment with the culture and society. At the end of the poem, Behn just shows her disappointment to Lysander. She says
Whose soft bewitching influence,
Had Damn’d [Lysander] to the Hell of Impotence. (Behn 140)
She is giving up elaborating her feeling because she knows her audience (men) would not understand it. Women are silent in the communication is caused by the culture in that period, which suggested that she is not only disappointed to Lysander’s impotence, but also disappointed with the culture, in which women are silent and objectified.
Further, Lady Mary points out that how women are objectified in The Lover: A Balled. She says: “we harder like trees, and like river grow cold” before women lose their virgin. Women are saved and they feel save when they are transformed to object illustrated that how women are treated in that period. Women are not only objectified, they are also to be ignored since they do not have a change to talk and express their emotion. Besides, women’s low social position can also be found when Lady Irwin says she is vapor in her poetry. Hence, Behn is disappointed to the culture, in which women are objectified and they have to remain silent.