We're pretty sure that a man's fiance showing up and crashing his bachelor party, in Las Vegas no less, is every guy's nightmare -- no matter how hot you look. But that's what happened to actor and 'Extra' host Mario Lopez.

He began his bachelor party weekend extravaganza at TAO Beach in Vegas on Friday afternoon, and even tweeted his excitement about it all - like every good soon-to-be hubby does. "Just checked in.. Heading to the pool for some drinks, then a little gambling…," he wrote. "Dinner & club later… 15 of us guys here! #DeepEntourage."

But unbeknownst to him, his fiancee and baby mama Courtney Mazza had a little trick up her sleeve. As a surprise for Lopez, she conspired with Robin Antin, creator of the Pussycat Dolls Show in Vegas, and performed with the group as a surprise for her betrothed.

As evidenced by a photo she later tweeted, Courtney rocked red gloves that read "I heart Mario" and a bustier that made her rack look great. Fortunately for her, Mario loved the show -- but isn't the whole point of a bachelor party in Vegas to check out boobs that don't belong to your girlfriend?

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