A teams disco is when everyone in the class opens a file saved on teams that Ms G. has open and everyone moves their cursor around the screen clicking on the text. Because it is a shared file you can see everyone one else's cursor and they're all coloured differently, so on Ms G.'s screen you can see everyone's cursors lumping around the screen like disco lights.
"Guys, can we please not have a teams disco so that I can read the powerpoint?" - Ms G.