Obsession

"He wanted his fun--with no commitments
Nicola knew all the reasons why she should remain nothing more than Lang Hyland's secretary. That was all she ever intended to be
Lang was a womanizer. He preferred big-eyed blondes, but his interest waned after three months. Nicola had watched enough women tearing their hearts out over him to feel immune.
Then why, she asked herself, should she feel so upset when he again made his position clear? ""I've absolutely no intention of getting married,"" Lang said, ""and I know you wouldn't consider anything else."""