To make the dressing, thoroughly combine the mayonnaise, sour cream, jalapeño, celery, parsley, lemon zest and juice, salt and pepper. Add the chilled lobster to the dressing and let it sit in the refrigerator for 10 minutes.
2 Tablespoons mayonnaise, 2 Tablespoons sour cream, 1 small jalapeño, 2 Tablespoons celery, 1 Tablespoon fresh parsley, 1 lemon, 1 Tablespoon lemon juice, ½ teaspoon kosher salt, Pinch