The place of sexuality in God's plane was that the Eva and Adan multiplied and subjugated the earth according Genesis the first book of the Bible.
This union of the first human been in the earth had a purpose and it was reproduction. But the man sin changed all the context.
One way that the expression of plan of God has been distorted for example: many people think the woman must have many children taking literally the statement of the Bible mentioned and dont matter if the childrens coming from different parents.
The sexuality designed by God is to recreation, increase the relation to be together and placer for the husband and wife. All the things invented for the men which to be out of this statement from God is a distortion.
