Short answers, pulled from the story.
In 1819, King Francis I of Naples visited the Pompeii exhibition at the Naples National Archaeological Museum and was embarrassed by the explicit artefacts. He ordered them sealed in a cabinet accessible only to people of "mature age and respected morals". The Secret Museum was finally reopened to the general public in 2000.
The Lupanar was the most famous brothel in Pompeii and the first to be officially identified. It had ten rooms arranged five per floor, along with a balcony and a latrina, and its walls were covered with erotic paintings and graffiti. In 1995, Andrew Wallace-Hadrill confirmed its function by identifying three characteristic elements: raised stone beds, erotic art, and erotic graffiti.
Phallus imagery in Pompeii served protective and fertility purposes rather than purely erotic ones. The Romans used phallus depictions as wards against the evil eye, sculpted them as bronze wind chimes called tintinnabula, and placed them in gardens to encourage plant growth. The deity Priapus, depicted with an oversized phallus, was believed to be a talisman guarding a household's wealth.
Spintria tokens are small objects with a numeral on one side and a sexual scene on the other. One hypothesis links them to the dressing room of Pompeii's Suburban Baths, where eight wall paintings of sexual scenes were found above painted images of numbered storage boxes. The theory is that a token granted a bather access to the numbered box where they stored their clothing.
Venus appears in Pompeian artwork at least 197 times. The majority of those depictions are found in large common rooms and reception areas rather than in bedrooms, contradicting earlier assumptions about where her image would appear. Approximately one third of artwork featuring Venus depicts some kind of love scene.
Venus Pompeiana, or "Venus of Pompeii", is depicted standing rigidly, usually draped in a mantle with her right arm across her chest, and appears in highly visible locations with religious and ritual significance. Venus Pescatrice, "Venus the Fisherwoman", is always shown sitting, holding a fishing rod, and semi-naked; all known depictions share the same basic structure, suggesting a single unknown original source.