 In the sonnet, the speaker knows that his lover is lying about his age, but decides not to make much ado about nothing because he knows her act is dictated by love and concern.The irony is that the speaker is himself aware of the lie while hiding a lie of his own.Gerald Massey's "Shakespeare's Sonnets Never Before Interpreted" argues that this type of irony is a characteristic of a number of Shakespearean sonnets, particularly Sonnet 96, Sonnet 131, Sonnet 137, Sonnet 142, and Sonnet 147 (357).