Possible Clues:

• R-rated, perhaps
• Like mirrors you can write on
• Blue, like bathroom mirrors sometimes?
• Condensation-prone, perhaps
• Hot and humid — erotic
• Passionate group playing in Sleepy Hollow
• Erotic (informal)
• Erotic, like a Turkish bath
• Erotic extremes in story about sporty group
• Like a sauna group found in outskirts of Shrewsbury