Hey, dirty talk is great if it sounds inspired.  But if it comes across mechanical, it simply gets in the way.  Such is about half of Gutter Mouths.

The orally-optimal scenes, however, are No. 2, in which sultry Montana Gunn demonstrates low-key verbal skills even while stuffing cock down her throat, and the closer, which as luscious Brooke Ashley grubby-gabbing with gusto while getting d.p.'d.

To its credit, each of Mouth's four scenes contains anal and facial action.