My Dutch is a bit rusty, but I do believe it's mainstream.
Basically the guy bets the girl that she can't hold her arms up while he tickles her underarms for 2 minutes. The reason the cell phone is there is because they use it as a timer, which does go off toward the end of the clip. During the 2 minutes he tickles her, he keeps telling her to keep her arms loose, I think because she pinned her own hands under her head to keep the her armpits exposed.
After the 2 minutes are up, the cell alarm rings, and the girl congratulates herself. The one who is filming says he is still going to film, which is why the guy tickles her again, and this time the girl puts up a bigger fight.
I think it is mainstream; it isn't a dungeon; just a poorly lit living room.
Nice find!
