In Avengers: Endgame, during the brainstorming session with all the surviving Avengers, there is a scene where Nebula recalls that Thanos went to Vormir with Gamora, retrieved the Soul stone, and came back without Gamora. Then Scott Lang (Ant-Man) says "Not it" awkwardly.
What did it mean? Why did he say "Not it" in that conversation?
According to Urban Dictionary
"Not it" exempts a person from performing a deed provided he or she is not the last person to call "not it"
As an example, if your mom asks you to open the door and you say not it, you don't have to open the door. At least that's what I gather from UD.
Nebula didn't ask for a deed, she was just telling the story. Why did Ant-Man use "not it" in this conversation?