The Giuliana & Bill stars travelled to Europe earlier this year to get back in touch with Giuliana's roots and do research for their proposed Italian restaurant.
Speaking to Digital Spy, businessman Bill said that the vacation had made him realise how much E! News host Giuliana has achieved in her life.
"Giuliana was born in Italy and I got to experience what her life was like as a little girl. It was fascinating to see where she has come from," he said. "I'm really proud of how she came to America not speaking English and built this amazing life for herself. It made me more proud of her than ever and it was really great immersing ourselves in her culture."
Bill also told Digital Spy that he was able to prove his Italian speaking skills during the trip, which will be featured on the fourth season of Giuliana & Bill.
"I was able to understand what she was telling the waiter!" he said. "I was really hungry so I ordered two bowls of pasta because they served really small bowls, and I heard her speak to the waiter so I was able to say, 'Wait a minute! You just called me a fat American!'"
He added: "She was shocked I was able to understand her so now she knows she can't talk about me in Italian!"
Giuliana & Bill premieres Tuesday August 2 at 9pm on Style.
> Read more from Digital Spy's interview with Bill including his thoughts on visiting London and the British version of The Apprentice