Neil Patrick Harris Shows 'Late Show' A Clip Of His Toddler Playing The Slots In Las Vegas (VIDEO)

Proud dad Neil Patrick Harris showed off photos of his adorable toddler twins on "Late Show" (Weeknights, 11:35 p.m. EST on CBS) and proved that where parents are concerned, what happens in Vegas doesn't always stay in Vegas.

Harris recalled a funny thing that happened on the kids' first trip to Las Vegas. Proving that even the smallest ones can have fun there, little Harper was trying out one of the slot machines. However, that's a major no-no, and so casino security appeared within a matter of seconds.

David Letterman played a video clip of the incident and hilariously freeze-framed it just as a female security guard warned that there was a $10,000 fine for letting your kids play the slots. Harper was making a big "Oh!" face.

Harris joked that not only was Harper enjoying the slots, she also liked the free drinks that went with them.

"Late Show With David Letterman" airs Weeknights at 11:35 p.m. EST on CBS.

TV Replay scours the vast television landscape to find the most interesting, amusing, and, on a good day, amazing moments, and delivers them right to your browser.