....pointing out this allusion by Sheridan, it does seem to me to be very similar to Mrs. Malaprop's allusion to Hamlet, in that on the surface, Sir Anthony is trynig to convince Mrs. M to let bygones be bygones with Jack and let the young lovers do what comes naturally, but those who know the subtext from The Beggar's Opera can perceive that this is Sheridan putting words in Sir Anthony's mouth that function as a kind of unconscious confession of his own lecherous feelings, born of a sense of loss of his own youth. He is a narcissist who cannot simply be happy for his son's having found true love, but instead has barely controlled desires to get in on the fun himself. And perhaps, given the group that MacHeath (so that's what the song Mac The Knife is about!) addresses when he is singing that song, it's also a bit of a shot at Mrs. M!