Miss Robinson and the Unsuitable Baron by Sofi Laporte

A proper schoolmistress, an aristocratic nincompoop, and an improper proposal.

When Ellen Robinson seeks out Baron Edmund Tewkbury in London to deliver his ward, he wheedles her into staying—as his wife.
Edmund Graves, Sixth Baron Tewkbury, is in a pretty pickle after lying to his friend about being married. To save face, he must introduce a fictitious wife at a high-society house party. But where does one obtain a wife at the snip of one’s finger, especially when one isn’t keen on being married?
Miss Ellen Robinson is a respectable school mistress with no prospects of marriage. All she wants is to deliver Baron Tewkbury’s ward and return to her beloved seminary in Bath. When the baron makes her a shockingly improper proposal in exchange for assistance with her own family troubles, she finds it impossible to resist.
As she gets sucked into a whirlwind of scandal and deceit, Ellen discovers a most surprising thing: behind the mask of the nincompoop hides a very different man. Navigating the duplicity of their fake marriage, Ellen and Edmund realize their feelings for each other might not be as feigned as they thought. But how can true love prevail in this web of lies?