I've always wondered how that worked too..
Just sitting around bored one night, decide it's time for action.. Call her up, "So, uh.. you wanna, like, do it n' stuff" "Sure, come on over." uNF uNF uNF "Welp, cya later." "Yup, cya." Just like calling up guy friends to see if they wanna hang out on a Friday night an play PS2 or whatever. Seems odd.
As you can tell, my answer is no. Either fall into the relationship zone or the friend zone.. Nothing in between.