This was a good idea of his, he thinks. He's been dying to get out of the bar for a while and he likes Miami - hot, beaches, women in bikinis everywhere, nice cars, plenty of good stores to blow cash in. They could both do with a day away and it'll be nice to be able to spoil Fi. Nice to be able to show off some of his immense wealth too, obviously.
But he only knows the city in general, not where a woman would like to shop. So when they get through the door, he just turns to her and says,
'I'm in your hands. Where to?'