They shoukd repent to Allah and ask Him for forgiveness. They should wait until they can get married but they should not communicate at all as they are strangers.

Two friends of mine (one female and one male) are seeing each other, they have plans to getting married as soon as my (male) friend graduates and gets estabilished.They suddenly come to know that the Girlfriend and Boyfriend relationship is strictly forbidden. They already like each other and refuse to accept any proposal from any third party, now what should they do?