Married by morning - Lisa Kleypas

For two years Catherine Marks has been a paid companion to the Hathaway sisters - a pleasant position, with one caveat.
Her charges' older brother, Leo Hathaway, is thoroughly exasperating.
Their constant arguing has masked a mutual attraction.
But when one quarrel ends in a sudden kiss, Cat is shocked at her powerful response - and even more so when Leo proposes a dangerous liaison.
Leo must marry and produce an heir within a year to save his family home.
Catherine's respectable demeanour hides a secret that would destroy her.
But to Leo, Cat is intriguing, tempting.
The danger Cat tried to outrun is about to separate them forever - unless two wary lovers can find a way to banish the shadows and give in to their desires...