From puberty, boys are sexually attracted to girls and girls to boys. This feeling is good and God-given but intended for marriage and must be guided by God.
“Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.” – Genesis 2: 24
“I will praise thee; for I am fearfully and wonderfully made: marvellous are thy works; and that my soul knoweth right well.” – Psalm 139: 14
“I say therefore to the unmarried and widows, it is good for them if they abide even as I. But if they cannot contain, let them marry: for it is better to marry than to burn.” – 1Corinthians 7: 8-9