15 and 20.
Dating is not legislated. Most people would consider it morally wrong.
If you're sleeping together, the law in most states sees it as you raping a minor, i.e. statutory rape.
There is no law against it. However there are laws about sexual contact and the older party could be charged with sexual crimes depending on the state or country.
you should only date if you plan on getting married. enjoy being young and
wait to date until you are ready for marriage. that means no sex!!!until
marriage!!!