Is it right for a christian brother to be in a relationship with a girl and also to romance a girl?
The answer is NO. It is not right for a Christian brother to be in a relationship with a girl except both of you are in a courtship agreement. A Christian brother can have lady friends who should be treated as sisters in the Lord. But when it comes to picking a particular sister for a relationship, it becomes very risky because you are not yet ready or you cannot guarantee that you must marry her.
Secondly, romancing a girl should not be in the dictionary of any body who calls himself a Christian brother(the same applies to all Christian ladies). The girl's body as well as your own is God's property/temple and we are all bought at a price which is the blood of Jesus Christ.
Never go beyond boundaries. Treat her as a sister with all purity(1Tim.5:1-2) because the Bible warns that anyone who defiles the temple of God, him shall God destroy(1Cor.3:16-17). Please do not use your today to spoil or destroy your tomorrow. Be holy even as your Heavenly Father is holy.
Matthew 5:27-30, Luke 16:12 and 1Thess.4:3-7 will also help you to understand the stand a Christian ought to take in these matters. Submit all desires to God and He will help you overcome those temptations. Flee from fornication, resist the devil and he will flee from you.
Remain richly blessed..