What is the ruling regarding a girl who loved a man and he promised to marry her, claiming that she was his wife before God, and they met in an apartment to practice marital life, with the exception of penetration, then he left her and returned to his wife?

The girl and the man erred by committing sins, for Islam does not approve of a relationship between a man and a woman before marriage. What the man did was not a legitimate marriage, as it lacked the necessary conditions.

Both must offer sincere repentance by abandoning the sin and severing the relationship, feeling remorse, and resolving never to return to it. They should also conceal their actions, in accordance with the saying of the Prophet, peace and blessings be upon him.