Add the mayonnaise, yogurt, and 4 ounces (1/2 cup) of the blue cheese to a bowl.
Use a fork or a small masher to mash the ingredients gently.
Add the vinegar, lemon, Worcestershire, hot sauce, garlic, pepper, sugar, and parsley to the bowl.
Mix well and add an additional 2 ounces of blue cheese crumbles.
Cover the dressing and let it hang out in the fridge for at least 3 hours.
Notes
Make this a few hours in advance for maximum flavor.Depending on your preferred consistency, you may need to add a splash of milk or half-and-half to thin it out.A touch of sugar helps balance out the acidity, and a little goes a long way. I suggest you taste the dressing before adding it. I love an acidic dressing and don't always add it.