Allah created the sexual desire in humans. It is as normal as is the desire for food or shelter. Like other desires that Allah created in humans, it is powerful and can overwhelm a weak human. Sexual desire, like the desire for food, can be satisfied legally or illegally.
But we have to stress that Islam is aware of educating people on the proper way of satisfying their desire in the light of its noble teachings. In seeking this knowledge, shyness does not stand as a barrier in this case, but such knowledge must be imparted in a modest and dignified manner. Almighty Allah says, “Say (unto them, O Muhammad): Are those who know equal with those who know not? But only men of understanding will pay heed.” (Az-Zumar: 9)
If the conversation is such that the topic of sex is taken lightly or joked about, it should be avoided. Also, one should not divulge details of his or her intimate conduct for the Prophet (peace and blessings be upon him) said, “Among those who will occupy the worst position in the Sight of Allah on the Day of Resurrection is the man who has intercourse with his wife and then spreads her secret.” (Reported by Ahmad, Abu Dawud, and Al-Bazzar)
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: If such conversations have any meaningful educational purpose, and they are conducted within the permitted limits of Islamic ethics governing such talks, there is nothing wrong with such talks. During the time of the Prophet (peace and blessings be upon him) men and women used to raise questions relating to sexual matters in public in order to seek Islamic guidance.

So we must ask ourselves: Are there any tangible purposes or benefits in such conversations? If the answer is no, then they fall definitely under the category of major sins. The Prophet (peace and blessings be upon him) emphatically stated that there is no salvation possible unless we guard our tongues. He said, “Most people enter hell fire because of what their tongues have harvested!” He also said, “Whoever guarantees me that he will guard his private parts and his tongue and keep them pure and chaste, I will guarantee him/her paradise!”
Furthermore, engaging in such conversations may also inadvertently lead people to fornication or adultery. This is why the Prophet (peace and blessings be upon him) said: “The eyes commit adultery, the tongue commits adultery, the hands commit adultery, the feet commit adultery, the private parts finally either consummate it or repudiate it!”
Now, what should a person do when faced with such situations? The answer is: you should walk away from them if possible, or change the topic. If that is not possible either, then occupy yourself with some other business and hate the thing in your own heart. Allah says that one of the traits of the Servants of the Merciful is that “When they pass by idle chatter, they pass by with dignity!” (Al-Furqan: 72).