Green’s Dictionary of Slang

cock adj.2

[cock n.4 (1)]

(US) pornographic.

(con. WWII) K. Cook Other Capri 127: [Europa and] the bull [...] I’ve heard a lot of cock stories, but that one – [HDAS].
[US](con. 1970) J.M. Del Vecchio 13th Valley (1983) 43: Now you wanta hear a cock story [...] do I got some good shit to lay on you.

In compounds

cock book (n.)

(US) pornography.

[US]J. Webb Fields of Fire (1980) 140: I don’t want all these magazines and cock books just laying around.
[US]Simon & Burns ‘Combat Jack’ Generation Kill ep. 4 [TV script] ‘How do yuo jerk off with no hand?’ ‘You go to have one hand . . . to hold the cock book’.
[US]D.R. Pollock Devil All the Time 96: ‘[D]on’t you let somebody walk in here and catch you looking at that damn cock book’.
cock movie (n.)

a pornographic film.

[US]D. Simmons ‘Terms Used in a Men’s Dormitory’ in AS XLII:4 228: cock movie, n. phr.; horn movie, n. phr. An erotic ‘dirty’ moving picture.
[US]Memoirs of Dee Dee 120: The art form I practice — an art form the vulgar refer to as cunt and cock movies.
[US]E. Asinof Say It Ain’t So 147: The night before the attack they were shown cock movies.
[US]T. Shaw The Way Life Should Be 145: They sound [...] like some triple-X cock movie.
[US]J. Davies Mr Perfect 75: It was a cock movie! A crude porno set in an office.