Christian dating verse
As I've written on this site before, "practice" and "recreation" are not good reasons to date.
Dating is for the purpose of finding a marriage partner.
If you don't desire that sort of protection or aid, at least insist that the two of you begin to meet with others who know one or both of you well so that there will be consistent accountability and an outside perspective on how the relationship is going.
Humble openness to accountability is essential to a godly relationship. It's not exhaustive coverage, I realize, but this should at least get your relationship started on broad principles.
It is simply God's design and assignment of equally valuable roles among spiritually equal beings. Briefly, biblical support for this position is found, among other passages, in the creation order in Genesis 2, in 1 Corinthians 11: 7-9, and Ephesians 5.
The command in Genesis to be fruitful and multiply is a general command. As it is the man's God-given role to initiate, so it is the woman's God-given role to respond.