Poor Jlo's always getting teased by the guys on "American Idol," but last night her boyfriend was the brunt of the jokes!

Jennifer Lopez is dating much younger, and much shorter hottie Casper Smart, and he's often in the audience at American Idol to support her.
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The 24-year-old backup dancer, by now, is buddies with Randy Jackson and Steven Tyler, and he gave them a warm greeting when he arrived. But Ryan Seacrest is a different story. During the commercial break, Ryan pointed out Smart chatting with two pals in the audience.

Seacrest said: "Which of these three guys is Jennifer's boyfriend?" Adding "Or is it the one who's shorter than Ryan Seacrest?" Poor Casper looked embarrassed, Jennifer doubled over laughing and the audience cheered. Now that's some good quality TV programming!

During the rest of the commercial breaks, Casper stuck close to Jlo's side, they chatted and stared at each other adoringly. The couple looked very much in love.