Miwaku No Dokushin Kizoku

In the Miwaku no Dokushin Kizoku (Bachelor Cousins) series:
V.1 - Kojou ni Tsudou Ai (To Marry McKenzie)
Greek tycoon Demetrios Karas can't concentrate. He's tried professional distance--and failed! Now he's in danger of blowing his whole business deal if he doesn't make his translator, Samantha Brewster, his mistress....
Satisfaction at last! As Demetrios expected, they are made for each other in the bedroom! Yet Samantha seems willing only to stay until the end of her three-month contract. Until a new commitment surprises them both--one that will begin in nine months....
V.2 - Nazomeita Bijo (To Marry McCloud)
Fergus McCloud couldn't quite remember how he'd first met Chloe Fox...but circumstances indicated that they'd slept together pretty soon afterward! Actually, they hadn't. But Chloe's mission was to persuade Fergus not to publish a book that would ruin her family. What better way than to prolong the pretense of their being lovers? Only, Fergus wanted to rediscover the delights of their night "together"—and he intended to be present this time...in mind as well as body!
V.3 - Ubawareta Kuchibiru (To Marry McAllister)
Brice McAllister, the world's renowned artist, instantly falls for Sabina as soon as he meets the gorgeous supermodel's gaze. He has agreed to paint her portrait only to quiet the insistent billionaire who demanded Brice to paint his fiancee's portrait at any price. The meeting arouses his desire to draw Sabina. However, once he starts to work on the portrait, Sabina does not hide her fear and avoids his gaze. It is as if she believes allowing him to draw her is a sin...
(Source: Shojo-Manhwa Scans)