Kate Upton's sending a message to her baseball star boyfriend -- get on your game or your gonna lose me ... to a guy who dresses up as a dragon for a living!
We got Kate BOUNCING (if you know what we mean) through LAX ... on her way back from Orlando, FL -- where, If you missed it, she got a marriage proposal from the Orlando Magic mascot over the weekend.
Thing is ... Stuff the dragon kinda snaked Kate's bf, Detroit Tigers ace Justin Verlander -- waiting until he walked away from their seats to pop the question..
Watch the vid (especially if you're Verlander) ... Kate says the proposal was a "huge honor" -- and definitely did NOT say she's turning down the dude who plays dress up.
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