Pitt, 46, and the girls headed out around noon for a trip to the Bonpoint collection of children's boutiques on the Rue de l'Université in the Left Bank.
Zahara, 5, and Shiloh, 3, were allowed to pick out their clothes. "Zahara chose very girlie outfits, but Shiloh only wanted items from the boys' collection, which is in another boutique across the street," one source tells PEOPLE.
She ended up picking out some acid-yellow boys' jeans, along with some shirts and cotton scarves.
After the shopping trip, they headed off to meet up with mom, who was on her first day of shooting The Tourist after doing prep work and relaxing with family – including dad Jon Voight – this past week in Venice.
Jolie, Pitt and the girls enjoyed lunch together at a suite in the Hotel du Louvre, near where Jolie, 34, was filming scenes outside the celebrated Comédie-Française theater.
After lunch, the girls and Pitt had a look at the set downstairs before heading back to their hotel – but not before Pitt was spotted giving Jolie a smooch.