Domizia Castagnini is a regular fixture in the Ducati garage and part of the inspiration for Bagnaia to secure his maiden MotoGP championship this year.
But their relationship got off to a rocky start when, after a dinner date in 2016, they had a minor car accident on the way home.
“We went for dinner at a restaurant in Turin,” Castagnini told La Stampa. “I remember it was raining that evening.
“After dinner, during the return trip, Pecco perhaps wanted to make a good impression with me driving the new car.
“To brag he skated a bit on the pebbles and after losing control we went to hit a pole: it just twisted the wheel and fortunately we did not get hurt.
“I laughed like crazy. He, on the other hand, was mortified.
“My parents never knew about this story before, otherwise they would never let me out again.
“They always thought that it was Pecco's grandfather, Antonio, who destroyed the wheel of the car.”
Castagnini’s uncle is Gianfranco Leoncini, a football legend of Juventus and Italy. She was friends with Carola Bagnaia, the Ducati rider’s sister and now assistant, before meeting Pecco.
"We've known each other since high school,” she said of Carola. “We went to school together and immediately established a good relationship. Pecco and I, on the other hand, went out in two different groups and then the two groups joined.”
Bagnaia the champion: "We woke up from stress"
Bagnaia completed the biggest turnaround in MotoGP history to overcome Fabio Quartararo, the 2021 champion, on the final day of the season to become champion for the first time.
"It was one of the best days of our lives,” Castagnini said.
"I was able to sleep thanks to the stress discharge. Pecco was not too well because of the tension accumulated in the previous days. The sleepless nights, perhaps, were those that preceded the Valencia Grand Prix. We couldn't rest well.
“We woke up all the time from the stress and I dreamed of the race."
Asked for the most difficult moments of Bagnaia’s career, Castagnini said: “There wasn't a bad moment in particular. Maybe in 2019 and 2020 when he was racing in Pramac.
“Those were complicated months because the results did not arrive and he was not calm. But we always supported each other and maybe that was the key to getting through that moment."
Bagnaia away from the bike: "He likes to get in the kitchen..."
Castagnini provided some amusing insight into Bagnaia away from the MotoGP world: "He collects shoes, sneakers.
“I remember once at the beginning of the year: he was in Qatar and I was in Pesaro. Through a mobile app I turned on and off the lights in the house. Immediately I got scared, then I realised that it was him, even if he always denied it!
“I like the determination he has to overcome obstacles and face the challenges that life throws at you. In addition to harmony and the ability to transmit love.
"He really likes to get in the kitchen. Usually he cooks at home, but because I always arrive late from work. He loves pasta. Returning from Malaysia he prepared the sauce for the tagliatelle and it was one of the best I tasted!”