The Director and Don Juan by Katy Regnery

Heiress Alice Story left her father’s company three years ago in a blaze of glory, inviting all of his employees to jump ship and join her, but only one accepted her offer: mail room clerk, Carlos Vega.
While Alice spent the next three years getting her own company off the ground, Carlos became her indispensable right-hand man — executive assistant and office manager, loyal counsel and trusted co-worker.
And all the while, they were quietly falling in love with each other.

When Alice is offered a lucrative business deal in Puerto Rico, island-born Carlos is the perfect person to accompany her on her trip as translator, but as they travel together from Philadelphia to Santo Domingo to Ponce, two unlikely co-workers will discover that during their three years working together, their feelings for each other have grown far deeper than they ever could have guessed.
And though business-minded, proper Alice will try her very best to ignore the longings of her heart, scorching hot, insanely sexy Boricua, Carlos, has no intention of letting her go.