I can only tell you of my experience, it may not be what happens to you. When I turn on my tummy at night, it is generally that in my sleep I am having a dream that is causing me to masturbate. Masturbating causes pee to build up very quickly and like you I wet the bed. Sometimes these dreams cause me to wake up a few seconds before I start peeing and sometimes just as it starts. I have never been able to get myself to get up to go pee at this point and although I am awake, the feeling and urge are just too strong and I let go. I used to feel guilty about it. But like you I am wearing a diaper. I figure, does it matter if now and again I use my diaper to pee and get relief from a very strong feeling, even if I am awake. Remember you are wearing the diaper for your comfort. If sometimes it is because you don’t know its happening and sometimes it is, is this important. My feeling is don’t feel guilty and don’t worry about which position causes more or less pee problems. You are stressing for nothing! What happens in your sleep is natural. My address if you still need to chat Navi_p2003@yahoo.co.uk