"We did a movie called When in Rome probably four months into dating," Bell told host Jimmy Kimmel. "We rented a scooter motorcycle in Rome. We were driving around the city and we stop at a gas station and he's pumping gas and talking to me casually."
"He lifts my helmet up and he goes, 'Are you crying?' I was sobbing," she recalled. "He's like, 'What happened?' I'm like, 'I burned my leg on the motorcycle and I didn't want to tell you.' He's like, 'How long ago?' I'm like, 'Four miles!'"
Bell said she burned her leg after unintentionally touching the side of the bike.
"It burnt a hole through my linen pants and gave me a very serious second-degree burn -- the muscle was exposed," she said. "But I was so desperate because he'd said to me as we stepped onto that bike, 'Careful about your legs on the side, it gets really hot.'"
Bell also said she got her motorcycle license to impress Shepard during their early relationship. The couple married in October 2013, and are parents to two daughters, 5-year-old Lincoln and 3-year-old Delta.
"They are stubborn as all get out," Bell said of Lincoln and Delta at the premiere of Like Father last week. "They get that from me."