No no no! WHOA!
Stop right there. There is nothing creepy in Snake Man's tweet about D&D.
D&D is a roleplaying game also known as Dungeons and Dragons. It is freeform storytelling, and considerably less weird and creepy than larping since it is usually played around a table with books paper and dice like a board game.
DM in this context refers to the lead storyteller or 'DungeonMaster'. In some variant roleplaying games the DM is instead referred to as a GM or 'gamemaster'.
Please be careful not to demonize a beloved nerd passtime. Tom Hanks already tried to do that in the movie Mazes and Monsters