another variation i have used.. (which actually happened to me)...works nicely as dreams are mysterious by nature, and women are fascinated by them.
'OMG, had a craziest dream last night....dont ask me why but you were in it!'
(EVERYONE wants to know about a dream that they were in)
'well?? what was it about?'
'nah its a little hectic to tell you, i dont know you THAT well

'
'oh come on!'
'ok well, lets just say that it was kinda...sexual, but thats not the interesting part.'
'well tell me!'
(at this point she knows that you probably dreamt of sleeping with her, and shes ok with it as youve just told her that the sexual aspect of the dream is not the main focus, and she is now waiting for the something else. You have got her to smoothly continue the conversation after imprinting the image of having sex with you in her mind....if there wasnt another interesting part to the dream, she would think TYPICAL MALE as the focus would be on f*cking her)
...anyway went on to briefly tell her that i was doing 'things' to this girl in my dream, and even though the girl didnt LOOK like her, in my dream i just knew it was her (youve probably had dreams like this too, you KNOW its a particular person but it doesnt quite look like them physically in your dream).
anyway the fact that there is this twist makes it not too direct as if im bluntly telling her that I dreamt of sleeping with her. Her first reaction to this was....
'ha ha are you SURE it was me though??'
(pretty much WANTING it to be her. If there wasnt this twist, the convo may have ended at 'umm it was kinda sexual'..unless she was already keen for some dirty talk but one cannot assume that.)
'Im pretty sure it was!'
'oh really...how could you tell??'
...from here you can take it ANYWHERE describing her body using descriptive language getting her as horny as hell eg. 'well as i was rubbing my hands up 'your' thigh...i noticed [something about her knobbly knee's/dress you have seen her wear etc]'
.....the rest is history...