Has impending fatherhood changed Matthew McConaughey? The Tinseltown Texan with a love of going topless sat down with David Letterman last night to promote his romantic comedy Fool's Gold, and, honestly, he wasn't looking that hot. But! After quizzing Matthew about "the baby" (due in late June, early July), David gave him a little ribbing about his penchant for going shirtless...and trotted out some old, alluring, and progressively-hilarious visual aids to prove his point. (Interestingly, Matthew seemed more entranced than outwardly amused by all the hot pics.) Clip above, and topless photos here, here, here and of course, here.