Preheat oven to medium heat. Grease the grill lightly
Clean tops of mushrooms with a damp cloth and remove stems.
In a small bowl, mix cream cheese, blue cheese, salt, pepper and hot sauce together.
Divide cheese mixture evenly into mushroom cavities.
Cut each slice of bacon in half. Wrap around mushroom and place a toothpick into the mushroom where the bacon ends overlap. {Make sure the toothpick is sticking out the side and is not in the top or bottom.}
Grill mushrooms 5-7 minutes per side or until bacon has grill marks, is slightly crispy, and the filling has melted.
Remove from grill, remove toothpicks and serve hot.