A source says, "They are very much in love. They have been sightseeing together in Campeche, and are extremely happy. Nick would not be anywhere else but by her side for this important occasion."
Earlier today the pair were spotted visiting some of Campeche's most famous tourist sites, including the Fort San Miguel. An eyewitness says, "They were holding hands, they looked really cute."
Over the weekend, more of Sofia's friends and family are expected to fly into the country to help her celebrate. Says a source, "She wants to have a big party with her nearest and dearest. She's determined to celebrate in style."