I'm fairly certain that the rotation won't make difference, as I believe that the sex animation orients 'up' by the property default and not the object it is placed on.
What I suspect will happen is that you will end up inside the bed based on it's rotational center point.
By all means though try it out, and let me know if my theory is correct.
Which gives me an idea on how to determine the number of clicks you would need to go up or down on any given bed. I'll do some experimenting later tonight and let you know if it works the way I think it will.
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