This Whole thing "sex with God" is extremely dangerous and Demonic. If you are a brave soul search on these two words "Incubus" and "Succubus"
Incubus: an evil spirit that lies on persons in their sleep; especially one that has sexual intercourse with women while they are sleeping
Succubus: a demon assuming female form to have sexual intercourse with men in their sleep.
In this Link you can read about masturbation and people who thought they were having sex with Jesus. but it really turned out to be demons. Though you need to scroll down a bit till you get to a heading "Sex with Demons"
http://net-burst.net/sexuality/masturbate.htm
PLEASE READ WITH THE MOST ABSOLUT CAUTION.