In Islam there no such thing called 18+.

In Islam there no such thing called 18+.

Rather Allah says what it means:

Tell the believing men that they should restrain their gaze (from looking at the women whom it is lawful for them to marry, and from others’ private parts), and guard their private parts and chastity. This is what is purer for them. God is fully aware of all that they do.

قُلْ لِلْمُؤْمِنِينَ يَغُضُّوا مِنْ أَبْصَارِهِمْ وَيَحْفَظُوا فُرُوجَهُمْ ۚ ذَٰلِكَ أَزْكَىٰ لَهُمْ ۗ إِنَّ اللَّهَ خَبِيرٌ بِمَا يَصْنَعُونَ

Surat An-Nūr (The Light) - سورة النور

24:30
Tell the believing men to reduce [some] of their vision and guard their private parts. That is purer for them. Indeed, Allah is Acquainted with what they do.

24:31
And tell the believing women to reduce [some] of their vision and guard their private parts and not expose their adornment except that which [necessarily] appears thereof and to wrap [a portion of] their headcovers over their chests and not expose their adornment except to their husbands, their fathers, their husbands' fathers, their sons, their husbands' sons, their brothers, their brothers' sons, their sisters' sons, their women, that which their right hands possess, or those male attendants having no physical desire, or children who are not yet aware of the private aspects of women. And let them not stamp their feet to make known what they conceal of their adornment. And turn to Allah in repentance, all of you, O believers, that you might succeed.

My Allah help us to lower our gaze and not to look at what's forbidden.