Basically it is some new youtube challenge where they sit there and get all sorts of messed up and have to take the mess. They use a lot of savory stuff too. A lot of times it is people with their friends and family too (which is why I have not posted a link a lot of times a younger sibling is messing them up, so kids in video are a no go on here). but just type it into youtube it is really awesome!

I think they might be connected to Debb and Chris who do nasty messy challenges to raise money for charity.

It's not a new thing, but this 'Messy World' guy has been reuploading a bunch of videos of various ages with new titles.

tl;dr: 'girl take pie in face' is a new thing.

Yeah, very much not a new thing, ABC3 was doing it more than 4 years ago:
https://www.youtube.com/watch?v=wZw8mkzNKcE

Whether they took it from the internet or vice versa, its been around. But enjoy, still new to some I imagine.

I have seen that video but I did not realize it had really hit the internet enough for youtube people to do it haha from what it sounds it is a charity thing as well.