It means to go somewhere with the intention of having sex with the person you're going with.

Short for in other words: hang out with your wang out, rock out with your cock out, Trick out with your dick out, Greet out with your meat out, School out with your tool out, Ring out with your thing out, Wad out with your rod out, Roast out with your toast out, and Roll out with your roll out.

When you eat dirt for the first time and leave your family to build a shack in the woods