slip of the pen

give someone the slip

To evade, escape, or get away from somebody.

let slip

To divulge a secret, as by accident or mistake.

let something slip

To accidentally reveal a secret.

pen picture

A written description, often biographical.

pink slip

A notice of termination of employment.

poison pen

A manner, means, or tone of expression had by a written work, characterized by spitefulness, defamation, and/or intimidation directed toward a person, organization, or point of view.

put pen to paper

To write something (especially using pen and ink).

slip back to old ways

to return to past bad habits