When the ambassador met the heiress

MEXICO CITY -- Tony and Mariasun can't stop touching each other. They cuddle and smooch and giggle like teenagers and call each other mi amor. He lays his hand gently on her knee, and she strokes it as if she's been doing it forever, instead of just four months.

They talk for three hours about how they fell in love so quickly, about their sweet and awkward first kiss, about dancing until dawn and nuzzling in a dreamy Christmas Eve snowstorm, and about declaring their devotion on New Year's Eve with a couple of silver rings they bought for $20. They also talk about meeting Tony's old pals George and Laura at the White House and zipping around in Mariasun's private jet. It is a simple love story, with twists. Boy meets girl. Boy marries girl. Boy becomes billionaire.

They are known officially as Antonio O. Garza Jr. and Maria Asuncion Aramburuzabala.

He is US ambassador to Mexico, an old Texas buddy of President Bush, and the grandson of Mexicans. He is also the son of a gas-station owner in the border city of Brownsville.

He once served as Texas secretary of state and railroad commissioner, a position that regulates the state's vast oil and gas industries. He is 45, an affable and cheerful man who lives on a public servant's salary. His indulgences are fancy cowboy boots, golf, fine tequila, and modern art, and he makes no secret of having political aspirations at home.

She is one of Latin America's richest and most powerful women, a Mexican heiress who controls Grupo Modelo, which brews Corona beer, and whose family fortune weighs in somewhere around $1.5 billion. Her grandfather, who was broke when he arrived from Spain, founded the company, and she amazed Mexico's hyper-macho corporate elite when she fought successfully to keep it in the family after her father died in 1995.

She engineered lucrative deals to sell a large stake in the company to Anheuser-Busch Cos. and to take control of almost 6 percent of Televisa, Mexico's media and communications giant. She sits on numerous powerful corporate boards. She is 41 and has two sons from a 15-year marriage that ended in 1997. She is warm and laughs easily.

News of their engagement leaked out a week ago and became Mexico's hottest bit of gossip, and the source of a blizzard of questions. Would he resign? Would she move to Texas? Would she -- God forbid! -- become a US citizen? Would he -- Dios Mio! -- become a Mexican? Would the Bushes come to the wedding?

They laugh at all the speculation while sitting in the garden of his ambassador's residence, her truckload of tough security agents making his guys look like Cub Scouts. He shakes his head and smiles. He's blushing. She holds onto his biceps with both her slender hands and teases him: ''Ay, mi amor." They have a lot of ground to cover. But this is a love story, so what better place to start than with a first kiss?

He invited her upstairs to see his paintings.

It was last October. They'd been to lunch, then came back to his residence, which he has turned into a gallery of modern Mexican and American art. They wandered the first floor as he explained each piece. Then he asked her upstairs, where he told her he kept some of the best works.

She was skeptical.

''Then when I saw there were paintings, I started breathing again," she says.

She was leaving for New York on business the next day. He turned to her.

''This is always the hardest part," he said.

''What is?" she asked.

''You never know if you're supposed to kiss goodbye," he said.

She smiled. They kissed, very quick and tender.

She thought his schoolboy awkwardness was sweet. He was hooked like a tuna. She spent the next 10 days in New York. He called her every night.

''We talked for three or 3½ hours every night, until 2 or 2:30 in the morning," he says.

They had met after Bush named him ambassador in November 2002. Dell CEO Kevin Rollins was in town and the ambassador hosted a dinner for him and Mexican business leaders, with Mariasun the only woman at the table. Mariasun was in another relationship, and they saw each other only at social events over the next two years. Then her relationship ended, and they were each starting to see glimmers of possibilities.

On Sept. 9, 2004, Rollins was back in Mexico. Another dinner. The two had frequent lunch dates that fall.

Eventually came the kiss and the phone calls to New York, and in those 30-something hours of long-distance cooing, both of them knew they had fallen in love.

In November, Mariasun flew on a private jet to Brownsville to attend the wedding of Tony's niece. He introduced her as ''Maria from Mexico," nothing more. Photos stored in Mariasun's laptop show them sweaty and dancing all night, with Brownsville mud on her fancy pointed shoes and his boots. They returned for Christmas with his family, and as they emerged from midnight Mass, it was snowing in that steamy little corner of South Texas for the first time in 106 years. By New Year's Eve, they were in Cuzco, the ancient city in the Peruvian Andes.

''At that point we knew we wanted to spend our lives together," he says.