CHUCK - Were Adam and Eve "innocent" as to sexuality, or were they allowed all the privileges of a married couple except they couldn't have children while in the Garden of Eden? What was their sin?

JOEL - According to LDS prophet Joseph Fielding Smith,
"The transgression of Adam did not involve sex sin as some falsely believe and teach. Adam and Eve were married by the Lord while they were yet immortal beings in the Garden of Eden and before death entered the world" (DS 1:114-15; cf. JC, pp. 29-31)."
Therefore, since they were married, the Fall of Adam was not because of a sin against chastity. Adam and Eve were "man and wife" and were commanded by God to multiply (Gen. 1:27-28; Moses 3:21-25; Abr. 5:14-19). So any sexual relations they had were within the bonds of marriage and would not be considered sinful. However, we are not specifically told anywhere that they did have sexual relations while in the Garden of Eden.
Adam and Eve were completely innocent and did not commit any sin until after they were made mortal and left the Garden of Eden. What they commited when they partook of the fruit, was simply a transgression against a commandment, which was planned to happen, to open the way for the experiences of mortality. The LDS do not believe in the doctrine of the "Original Sin". No mortal person bears the burden of repenting for Adam's transgression. We have inherited certain effects of the Fall; we are born into a sinful world and eventually become sinful people, but we are completely innocent of any sin at birth.