To exit in an outward direction. As opposed to exiting inward. That's probably not even possible, but maybe like a disappearing girl in a magic act? Who know.
I cock pinching a house I thought had no alarm. But an alarm came on loud as hell. I turned to my partner arms up and yelled in frustration "Leave it OUT"
"It's so nice out, I think I'll leave it out" is a phrase used when stating pleasant weather. The phrase implies that the weather is so nice, you'll leave your dick out, hanging brain, because the coolbreeze feels so nice on one's genitalia.
Man, it's 73degreesoutside? It's so nice out, I think I'll leave it out!