Praise be to Allah.
Taking a girlfriend does not only destroy the family, it destroys society, and those who do this are threatened with the punishment and wrath of Allaah. Love is a sickness that destroys the heart and leads to evil and immorality. The Shaytaan will keep tempting them and pushing them until they commit immoral actions and thus each gets what he or she wants from the other.
There are many forbidden matters associated with this, such as transgressing against the honour of others, betraying trust, being alone with a member of the opposite sex, touching, kissing, speaking immoral words, then the greater evil which occurs at the end, which is the sin of zina.
The fact that the questioner says “no one knows about us” is strange. How can he forget about his Lord Who knows what is secret and what is yet more hidden, and who knows the fraud of the eyes and all that the hearts conceal. (cf. Ghaafir 40:19).
Our advice to you, as you are still young, is to discipline yourself to obey Allaah and always remember that He is watching; fear Allaah concerning people’s honour; strive for the Day when you will meet your Lord with your deeds; remember the scandal that may happen in this world and the Hereafter. Remember that you have sisters and will have a wife and daughters, so would you like for one of them what you are doing with the daughters of the Muslims? The answer is that you would certainly not like it, and other people do not like it either. Remember that you may see the results of your sin in some of your family members as a punishment to you from your Lord.
You have to look for righteous friends, and you have to keep yourself busy doing that which Allaah loves and is pleased with. Pay attention to the best and most sublime things and leave alone the worst and most vile things. Make the most of your youth in obeying and worshipping Allaah, seeking knowledge and calling others to Allaah. Remember that there were those of your age and younger who were men who had memorized the Qur’aan, who sought knowledge, whom the Prophet (peace and blessings of Allaah be upon him) sent to call others to Allaah and to enter the religion of Islam.
We advise you to get married to a righteous, religiously-committed woman who will help you adhere to your religion and encourage you to adhere to the laws of Allaah, who will look after your children and bring them up with good morals and religious commitment. Give up this woman who agrees to go out with a man who is a stranger to her (a non-mahram) and meet him and talk to him; if she agrees to do immoral actions now then what is going to prevent her from continuing to do so in the future?
Remember that you are angering your Lord with such sins as being alone with her, meeting her and talking to her, and anything more than that is even more serious.
You should realize that zina does not only involve the private parts, rather the eyes may commit zina, the ears may commit zina, the hand may commit zina and the foot may commit zina, as was proven from the Prophet (peace and blessings of Allaah be upon him). All of that leads to the zina of the private parts. So do not let the Shaytaan deceive you, for he is an enemy to you who wishes you evil and tells you to commit immoral actions.
Shaykh Muhammad al-Saalih al-‘Uthaymeen said:
Contact between lovers in improper and unlawful ways is a calamity and a real disaster. It is not permissible for the man to contact the woman in this case, or for the woman to contact the man. If he says that he wants to marry her, then he must tell her wali (guardian) that he wants to marry her, or she should tell her wali that she wants to marry him, as ‘Umar (may Allaah be pleased with him) did when he offered his daughter Hafsah in marriage to Abu Bakr and ‘Uthmaan (may Allaah be pleased with them).
But if the woman contacts the man directly, this is the source of fitnah (temptation).
As’ilat al-Baab il-Maftooh (Question no. 868).
With regard to your question about such forbidden relationships in the ancient love stories, the fact that such stories existed among those who came before us cannot be taken as proof with regard to shar’i rulings, because the rulings of sharee’ah having to do with what is forbidden and what is allowed are to be taken from the shar’i evidence of the Qur’aan and Sunnah, and the commands and prohibitions contained therein.
Some of those mentioned in these stories came before Islam, such as ‘Antarah and others, and such stories are to be found in other cultures as is well known. But we cannot take shar’i rulings from this because Islam came to bring people forth from being controlled by their desires to complete submission to Allaah the Lord of the Worlds.
We ask Allaah to guide us and you and to give us strength.