The punning on the word "will" continues from the previous sonnet. The poet wants to continue his sexual relationship with his mistress, but she is already bursting with lovers: "Whoever hath her wish, thou hath thy Will, / And Will to boot, and Will in overplus." Here in just the first two lines, the word Will appears three times, but just who or what these Wills are remains ambiguous. One possibility is that each Will corresponds to the youth, the Dark Lady's husband, and even Shakespeare himself. Another possibility is that Will is a general term for lover; after all, one meaning of the word "will" during Elizabethan times was the male sex organ. Yet another, less bawdy possibility, is that the word Will refers to the weak personalities of her lovers, who are unable to decide their own fates because of the woman's strong, sexually magnetic personality; basically she controls them, and they have no free will to make decisions.
Because the woman already has several Wills, or lovers, the poet wonders why she does not accept him, his "will," as well: "So thou, being rich in Will, add to thy Will / One will of mine to make thy large Will more." Employing the image of the sea as a simile of the woman, the poet argues that the sea adds water to itself without exertion; so should the Dark Lady.
There is more than a little cynicism in the poet's admission of lust for a thoroughly disreputable woman. Begging to have sex with the woman, the poet barely masks his jealousy of the woman's many lovers: "Shall will in others seem right gracious, / And in my will no fair acceptance shine?" What is so wrong, he asks her, with his sex organ that she won't accept him as her lover? Sarcastically, he bawdily asks her why her own sex organ, which so easily accommodated other men's, cannot accept one more.