It reads like: "Niina's erotic weekday — weekends are secretly touch stop" — possibly a title or lyric from an adult-oriented manga/doujin or game.
While specific details can vary depending on the release (game vs. audio CD), titles formatted like this are often: niina no ero youbi shuumatsu wa himitsu ni touc top
Here is an original short story piece that captures that specific "secret weekend" mood. It reads like: "Niina's erotic weekday — weekends
: Could be a name or a term specific to the context. niina no ero youbi shuumatsu wa himitsu ni touc top
: In an attempt to entertain her, the protagonist jokingly (or out of "luck") suggests doing something "lewd".