During an appearance on The Doctors, Asghari opened up about the nickname, explaining that he chose the moniker because of how much Spears inspires him.
"If you guys watch the Geography channel, I watch it all the time. The female lion inspires the male lion all the time," he said. "The female lion, I give props to you guys," he told the women in the audience. "I have three sisters, and so they inspired me."
"I was raised by women, and I think you guys are amazing, so that's where that came from," he continued. "Lioness is a strong, strong animal and yeah, that's it."
One way Spears inspires her boyfriend is with her dedication to fitness, with the couple often sharing Instagram videos of themselves working out together.
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"She inspires me on a daily basis when she works out," Asghari said, adding of their couple's workouts, "I think it's great. I think it's fun. You can inspire each other."
"I think couples should definitely work out together," he said.
Spears and Asghari made their red carpet debut as a couple in July at the premiere of Once Upon a Time in Hollywood, marking a big step in their relationship. In a recent interview with Entertainment Tonight, Asghari shared that he hopes to eventually mark another milestone and marry Spears.
"This is something that every couple should do. That's the whole point of a relationship — we are a family," he said. "Trust me, if we do ever get married, everybody's going to know."
The 25-year-old, who was born in Iran, also opened up about how the couple's families are getting along, sharing that his mom and sisters have all met Spears.
"I have three sisters. We've hung out a lot of times," he said. "We've been together for three years and my sisters love her, my family loves her. My mom lives in another country [but] when she was here, she met her."
Spears is mom to two sons, 13-year-old Sean and 12-year-old Jayden, with Asghari calling his relationship with the boys "absolutely amazing."
"What I love the most about my relationship is the fact that it's so normal," he said. "It's not glamorous or anything. She inspires me in my work and I can give so much to her by going to the gym, by going to work, by having a balanced life. We can get inspired by each other here and there and really grow with each other."
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