Kate Beckinsale’s Teen Daughter Takes Secret Videos of Her Dancing: ‘It’s Going to Be There to Ruin Me!’

Underworld: Blood Wars star Kate Beckinsale loves to dance.

So much so that the actress, 43, and her daughter Lily, 17, “do those YouTube videos where you have to follow along,” she tells PEOPLE in this week’s issue. “They’re really difficult. But oh my God, you can’t stop doing them. It’s like doing a triathlon, you spend about three hours doing it and you’re kind of exhausted afterwards.”

For more of Beckinsale’s One Last Thing interview, pick up this week’s issue of PEOPLE on newsstands Friday

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Beckinsale insists her own skills are limited when it comes to choreographed moves. “You have to do it as it’s happening in real time so you don’t get to practice,” the actress adds. “But she’s pretty good at it. We don’t have a large audience, fortunately. She meanly and secretly makes videos of it on her computer so it’s going to be there to ruin me.”

As for her other fears, Beckinsale admits she also gets irrationally scared “when people vomit. That’s my worst thing,” she says with a laugh. “So if someone is on the phone with me in like a distant state and says they have the stomach flu, then I am hitting the hand sanitizer quite hard.”

“Like if you were bleeding to death, I would help you but if you were vomiting, I will be long gone. With my fingers in my ear. Goodbye. Sorry,” she adds. “I’m a very supportive friend unless that happens.”