Prank Wars
Nat, Steve, Bucky, Tony and Maria were all on a mission, and Pepper was busy, leaving the others to their own devices (not a good idea)
It was debatable who started it; it might have been Clints fault for stealing Wanda's headphones, or it may have been Wanda and Robin's fault for cranking him.
Either way, the Prank Wars began; Steve, Robin, Wanda, El and Max against Clint, Dustin, Will and Peter.
Wanda's team had more people, but Clint was an adult so it was pretty fair.
The first thing they did was use El's powers to know what everyone was doing, and use Wanda's and Robin's to burst the water pipes over all of their rooms, apart from Will's, because he would probably have enjoyed it.
It took a bit out of them, but it was all worth it to hear Clint's outraged yelps as he was washed out of the vents.
In retaliation to that, they got Dustin to grow tiny stumps all around their room while they were sleeping, but forgot that Wanda could fly, so had to run from an angry Scarlet Witch.
It was all worth it, though, to see Steve's expression when he woke up.
They carried on like this, back and forth, until the others returned to the mess they had left in the compound.