Search - The Christmas Bride (Harlequin Presents)

Silas Stanway is furious! How did he end up playing escort to Tilly at a Christmas wedding in Spain? He expects her to be scheming and desperate. Instead she's sweet and honest. But why does she need to hire a man?
When they share a room, Sials assumes this must be part of his escort duties. But he's wanted Tilly from the moment they met-whatever the consequences....

a woman hires and escort to go with her on a trip and pose as her fiancee. the trip is to a wedding for her mother, who is marrying some infamous oil tycoon. the "escort" turns out to be a reporter who goes along with everything because he wants the goods on the tycoon

A good read. Heroine is slow to give in to her attraction to the hero, which is rare for a HP heroine.