Stiff Drink: Arthur Duet #1 by Blair Babylon

Genevieve is a lawyer, not a babysitter, and certainly not a dog trainer.
She is just about to become a full barrister, a British litigating attorney, when her law mentor dies unexpectedly. She is shuffled off to another barrister, one who’s nothing at all like her kind and decent former mentor, and then she is assigned the office’s worst case: Arthur Finch-Hatten, six-feet and four-inches of ripped, loaded, hot English nobleman who is wasting his life and his inherited estate so audaciously that his younger brother is suing him for control of their family’s earldom. There is a darn good chance that Arthur will lose everything, even his crazed, badly behaved puppy.

Unless he shapes up.

Gen’s new boss hasn’t been able to convince Arthur to mend his ways. His uncle’s lectures haven’t had any effect on his depraved debauchery and lavish lifestyle.
The only way for Genevieve to make partner is to win Arthur’s case, and the only way to win his case and save his earldom is to keep him from spending his days hungover in bed and his nights pouring Cristal on drunk, naked women before flying off in his private jumbo jet to the next party.

Arthur is enough to make any woman need a stiff drink.