Edit
between_pectorals middle_of_pecs on_pecs
When an object other than a penis fits or is pressed between the pectorals. If it is a penis, use pecjob instead.
Related tags:
object_on_pectorals: Similar to object on breasts, but with pectorals
pecjob: Act where a penis is rubbed between pectorals
pectoral_grab: The act of grabbing or groping pectorals
pectoral_docking: When two sets of pectorals are pressed against each other.
Nobody here but us chickens!