Read it through once

Stanza 3, vv. 1-4. The speaker knows that this beau monde does not proscribe love, provided it be in accordance with the proprieties which IT has determined upon and established. v. 5. “The world’s good word!” a contemptuous exclamation: what’s the world’s good word worth? “the Institute!” (the reference is, of course, to the French Institute), the Institute! with all its authoritative, dictatorial learnedness! v.6. Guizot and Montalembert were both members of the Institute, and being thus in the same boat, Guizot conventionally receives Montalembert. vv. 7 and 8. These two unconventional Bohemian lovers, strolling together at night, at their own sweet will, see down the court along which they are strolling, three lampions flare, which indicate some big place or other where the “respectables” do congregate; and the woman says to her companion, with a humorous sarcasm, “Put forward your best foot!” that is, we must be very correct passing along here in this brilliant light.