When it comes to finding synonyms for the term "mistress house," there are a few different options that you can consider. For example, you might describe a mistress house as a secret retreat or a private abode where a mistress and her lover can meet in private. Alternately, you could use terms like a love nest, a romantic hideaway, or a discreet rendezvous spot to describe the same thing. Ultimately, the right synonym will depend on the context in which you're using the term and the connotations you want to convey. Whether you're writing a romantic novel or a scandalous news article, choosing the right words will help you paint a vivid picture.