An Outdated Adult Joke
The episode was titled The Last Babysitter, the eighth episode on the third season of Rugrats. When a replacement babysitter is desperately needed to watch over the kids, a series of candidates were asked if they could sit in for the job; the Deville’s were not available because, based on Sty’s statement, they are in Vegas for the weekend.

Source: Twitter
Howard also had plans to go camping with his ‘male bonding’ group, and as he was saying this, the hand gestures that accompanied his line spelled it out.