*DJ Khaled voice* ANOTHA ONE! And its a romantic version of... Mrs. Doubtfire? Nice try, Katie, but also weirdly, yes exactly. Sofi Laporte's Lady Avery and the False Bulter features a handsome rogue in hiding and a pissed off spinster who just wants to have some fun (and upon further thought, maybe not empty her own chamberpot). 

https://www.goodreads.com/book/show/123238138-lady-avery-and-the-false-butler?from_choice=false&from_home_module=false

And if you're looking for something similar:

Miss Ava's Scandalous Secret by Sofi Laporte

https://www.goodreads.com/book/show/60756662-miss-ava-s-scandalous-secret

Lady Ludmilla's Accidental Letter by Sofi Laporte

https://www.goodreads.com/en/book/show/60391368

The Bridgertons Series by Julia Quinn

https://www.goodreads.com/series/40393-bridgertons