 Mendes encouraged some improvisation ; for example , when Lester masturbates in bed beside Carolyn , the director asked Spacey to improvise several euphemisms for the act in each take . Mendes said , " I wanted that not just because it was funny [ ... ] but because I didn 't want it to seem rehearsed . I wanted it to seem like he was blurting it out of his mouth without thinking . [ Spacey ] is so in control — I wanted him to break through . " Spacey obliged , eventually coming up with 35 phrases , but Bening could not always keep a straight face , which meant the scene had to be shot 10 times . The production used small amounts of computer @-@ generated imagery . Most of the rose petals in Lester 's fantasies were added in post @-@ production , although some were real and had the wires holding them digitally removed . When Lester fantasizes about Angela in a rose @-@ petal bath , the steam was real , save for in the overhead shot . To position the camera , a hole had to be cut in the ceiling , through which the steam escaped ; it was instead added digitally . 
