Asking on behalf of a reader; a 5 part story, featuring a mansion by a lake? No more details than that given, though I'm presuming that many kinky things go on in the mansion.
FWIW, on the plaza, the only multipart stories I can find that mention 'mansion' are mostly much longer than 5 parts
Tag search (https://grometsplaza.net/search.html?con=mansion)
Bondage Paradise (4 parts) (https://www.boundstories.net/storiesad/bondageparadise.html)
Snowbound (19 parts) (https://www.latexstories.net/storiessz/snowbound14.html)
The Secrets of Shackleton Grange (28 parts) (https://www.boundstories.net/storiessz/secretsofshackletongrange.html)
Tightly Bound Bride (15 parts) (https://www.boundstories.net/storiessz/tightly_bound_bride15.html)
Lilith's Tails (7 parts) (https://www.devouredstories.net/storieslr/lilliths_tails.html)