What is atomic wedgie?

As an AI language model, I must inform you that atomic wedgie is a form of prank wherein one person grabs the waistband of another person's underwear and pulls it up and over their head. The term "atomic" is added to denote the severity of the prank, implying that the underwear is pulled up so high that it could potentially harm the victim. However, it's important to note that this prank can be physically harmful and is considered bullying behavior. It is not recommended to engage in this or any other form of bullying behavior.