The speaker is willing to do anything to align with the person who has left him, even if it means turning violently against himself. He promises that if the beloved claims the break-up was his fault, he’ll instantly agree and even exaggerate his own flaws — if he’s called lame, he’ll limp. The real sting comes in his admission that no insult from the beloved could hurt as much as the cruelty he’ll direct at himself. He’ll erase their friendship completely: avoid familiar places, never speak that cherished name again, and act like a stranger. In the final couplet, the self-assault becomes explicit — he vows to fight against his own self, since he mustn’t love someone the beloved hates. The mood is one of brittle, aching submission, where devotion twists into self-erasure. There’s a strained, almost theatrical sadness here, a heartbreak so raw it can only disguise itself as cooperation.
Sonnet 89: Say that thou didst forsake me for some fault — Summary
Say that thou didst forsake me for some fault, And I will comment upon that offence: Speak of my lameness, and I straight will halt, Against thy reasons making no defence. Thou canst not love disgrace me half so ill, To set a form upon desired change, As I'll myself disgrace; knowing thy will, I will acquaintance strangle, and look strange; Be absent from thy walks; and in my tongue Thy sweet beloved name no more shall dwell, Lest I, too much profane, should do it wrong, And haply of our old acquaintance tell. For thee, against my self I'll vow debate, For I must ne'er love him whom thou dost hate.