The best way to get to second base with Katherine McPhee -- ask her to prove she's never had a boob job!
After jiggling her rack for the audience at "The Tyra Banks Show," Tyra asked the stacked "American Idol" runner-up if she could cop a feel to help dispel any rumors that she was artificially enhanced. Slick, Tyra!
Tyra went for it. Hardcore. You're welcome.
Feel the McPheever when the episode airs Tuesday.