Now this episode is REALLY funny. for some reason most of the episodes involving Stewart usually are.
Beavis and Butthead are watching TV when Stewart's mum knocks on their door to ask if they have seen him. Butthead says no and slams the door in her face. She knocks again and basically asks them to help her find him.
They do help for a little while, by putting up posters but they spend most of the time asking rather insensitive questions, enough to make poor Stewart's mum cry, but enough to make viewers howl with laughter.
This really must be one of the best episodes of them all, it really has to be seen to be believed as it is that funny. Of course Stewart is found in the end but where and why he was there is even funnier, but I'm not going to spoil that for you if you haven't already seen it. If you have already seen it then you will know it's a well funny ending.