He lends thee virtue, and he stole that word From thy behavior; beauty doth he give And found it in thy cheek; he can afford No praise to thee but what in thee doth live. (Sonnet 79)

In Sonnet 79, the speaker explains that the quality of his poems about the young man has declined because another poet also writes about the young man. However, the speaker believes that the rival poet did not even know the meaning of beauty or virtue until he saw the young man. As such, the rival poet essentially commits plagiarism every time he writes a poem about the young man, stealing what the speaker has already described for his own poems.

But he that writes of you, if he can tell That you are you, so dignifies his story. (Sonnet 84)

In these lines from Sonnet 84, the speaker explains that he believes no one can write a weak poem about the beautiful young man. He supports this claim by explaining that, as writing about a subject only improves the subject’s quality, and as the young man needs no improvement, no one could produce a bad poem about the young man. Such an opinion subtly undermines the rival poet’s talent, as anyone could write well about such a beautiful subject.

Was it the proud full sail of his great verse, Bound for the prize of all too precious you, That did my ripe thoughts in my brain inhearse, Making their tomb the womb wherein they grew? (Sonnet 86)

In Sonnet 86, the speaker questions if the rival poet’s work discouraged him from continuing to write his own poetry. He gives credit to his rival’s verse as effective, while he reminds the young man of their closeness. Readers may infer from these thoughts that the rival poet’s writing must be very strong and moving to be perceived as a threat by the speaker.

But when your countenance filled up his line, Then lacked I matter, that enfeebled mine. (Sonnet 86)

In Sonnet 86, the speaker explains his reaction when he saw that the beautiful young man liked a rival poet’s poetry. Whatever deficiencies existed in the writing, the speaker credits the young man’s approval as completing. The speaker finds such a collaboration defeating, and as a result, he could not write his own poems. As the rival poet has come into favor with the young man, the speaker believes the rival poet’s work will improve and he feels hopeless and powerless to match such a partnership.