Nasty Mama desires plump, sensitive cunt lips, and you're about to help her destroy her thick, meaty butterfly wings in exchange for a steamy, wet cunt load.
The speaker is discussing their attractive satin underwear and their anticipation for a big cunt underneath, with the promise of a pleasant scent after using cum and cream.
The speaker is referring to their mother's soft, but dirty cotton underwear, warning of a potential leak of poop and the unpleasant scent of MAMA's muffin.