The How I Met Your Mother star jetted to Sin City with his partner David Burtka and their 17-month-old twins Harper and Gideon for a small vacation.
But the funnyman admits he probably shouldn't have taken the tots to the casino - because Burtka almost ended up in jail.
During an appearance on U.S. programme The Late Show With David Letterman (29Feb12), he explained, ""I thought Vegas would be fun for little kids. To see all the lights, the blinking lights, all the waterfalls and water shows. I thought the Bellagio Fountains would be cool. It turns out they can't gamble...
""I thought all the turny wheels and video poker machines would be hilarious for them. We took them down onto the floor and it didn't go so well. Harper was trying one of the slots and within like 25 or 30 seconds an officer threatened to put David in jail.""
Burtka had documented the whole scene with a video camera and when Harris showed off the tape, a female security guard can be heard saying, ""It's against the law. It's a 10,000 fine.""
And in hindsight, Harris confesses the idea might not have been too smart, adding, ""They (the guards) are fast. Not a good move.""