Heat a grill or grill pan to medium-high heat. Reserve 2 or 3 of the scallions for serving.
Drizzle the corn and remaining scallions with the olive oil, season with a big pinch of salt and 5 to 6 turns of pepper and toss around so everything is coated. Place the scallions directly on the grill grates and cook, turning a few times, until charred, 4 to 5 minutes. Set aside.
Grill the corn, turning every couple of minutes, until nice and charred, 10 to 12 minutes depending on the grill (just keep cooking until they are the level of charred you prefer; be careful, they will pop). Remove from the grill and keep warm.
Thinly slice the reserved scallions and set aside.
Combine the cream cheese, sour cream and lemon juice in a mixing bowl and whisk until smooth.
When the grilled scallions are cool enough to handle, chop them finely and add them to the cream cheese mixture with the everything bagel seasoning. Stir to combine, taste and adjust the seasoning if necessary. (You will probably need to add salt if your everything seasoning does not have salt.)
Schmear the cream cheese mixture on the corn and serve topped with the sliced fresh scallions and additional everything seasoning.
Alternatively, this can be made into a dip: cut the corn off the cob, mix with the cream cheese mixture and fresh scallions, pour into a baking dish, top with any good melting cheese and bake until bubbly. Serve with pretzels or chips.