At The Greek Tycoon's Bidding (Harlequin Presents)

Heather meets wealthy businessman Theo when she moonlights as an office cleaner. Eventually they begin an affair after she is hired to help care for his mother. She develops more self confidence and learns to highlight her looks but when he ends things abruptly, she has to learn to start over. But then her selfish sister Claire returns and decides Theo would be a perfect catch.