Attachments: arises near the midline of on the anterior surface of the maxilla and mandible and modiolus at the angle of the mouth, and inserts into the mucous membrane of the margin of the lip, and the raphe with buccinator at the modiolus.
Action: narrows the orifice of the mouth , purses the lips and puckers lip edges.
Innervation: Buccal branch of the facial nerve, CN VII.

Definitely one of your kissing muscles.