Vaginal or anal intercourse.
We went down to the derelict casino where we came across Billyboy and his four droogs (friends); they were getting ready to perform a bit of the old in-out-in-out on a weepy young devotchka (girl) they had there - from the 1971 film "A Clockwork Orange"
by Anthony Brancato April 21, 2003
1 more definition
english slang term for sex, publicized in the movie clockwork orange
...so me and the other droogs were gettin ready for some of the 'ol in-out, in-out
by poosmack October 13, 2003