Jim Spellman / WireImage 1 / 16
Jim Spellman / WireImage 1 / 16

Gabrielle Union is arguably Dwyane Wade's biggest fan -- but sometimes it gets her into trouble.

The "Think Like a Man" actress, 39, isn't allowed to sit courtside while cheering on her Miami Heat beau. "That got killed when I became too vocal," Union explained on "Conan" Wednesday. "He was like, 'We're going to need you to sit a few rows back because I can hear you.'"

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"I'm like a dance mom: 'Plie! Plie!'" she explained. "I've become like Bobby Knight and like the Great Santini -- it's bad. I scream 'brick!' and 'air ball!'"

When host Conan O'Brien, 49, joked that she didn't sound very supportive, Union defended herself, saying: "Who's going to tell him if not me? I heckle other players on opposing teams."

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Union then provided an example: "There's a gentleman, who shall remain nameless, who was a little overweight, and I did yell out his name and 'Your Spanx are showing!' He looked at me -- because I time it perfectly for maximum effect -- and he looked hurt. Then I felt like an awful bully."

Athletes aren't Union's only targets. The actress, who's been dating Wade, 30, for nearly three years, said that she recently shouted at ref Dick Bavetta, 72.

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"He hadn't blown his whistle the whole game," Union recalled. "I said, 'You'll get your Viagra if you just make a call!"