The couple - who were first linked together at the Cannes Film Festival in France in May - put reports of a split behind them as they shopped for sunglasses in Santa Barbara on Wednesday (20.06.11).
A source told USMagazine.com: "They seemed very much in love. They were in the store for about 10 minutes before a crowd of fans noticed them and they rushed out."
This is the latest in a string of dates Leonardo, 35, has whisked the 'Gossip Girl' beauty away on.
Despite the fact the couple have refused to confirm their relationship, they have been seen together on a yacht in Disneyland, California, and on a water taxi in Venice, Italy.
Leonardo also treated the 23-year-old actress to a helicopter ride to Saint-Paul de Vence, France for a $500 lunch at La Colombe d'Or Restaurant, a stay at the $5,000-a-night suite at Hotel de Paris and a trip on a $52 million yacht and friends have revealed the 'Inception' star is determined to please Blake.
A source recently said: "I've never seen him like this with a girl."