Two things. 1.) If God didn't want people to masterbate, he would have put their sex organs in the middle of their back. 2.) Sex is defined by Wikipedia like this : Sexual intercourse, in its biological sense, is the act in which the male reproductive organ (in humans and other higher animals) enters the female reproductive tract, called copulation or coitus in other reference. I suppose it depends on your definition of sex. If it was me, I would go with what Wikipedia says and do anything other than that if I had those sort of religious convictions.