Mix butter, seasoning, parsley and lemon zest in a small bowl.
Place lobster tails on a cutting board with the shell upward.
Use a sharp knife to cut through the tail lengthwise. Spread the shell apart with your fingers and carefully pull out the meat from top to bottom.
Preheat the grill to medium heat.
Place tails on the hot grill, shell side down, and spread a little of the butter over the meat.
Cover the grill, cook about 5 minutes. Spread on a little more butter then flip onto the meat side and cook another 3-5 minutes.
Remove from grill, spread on remaining butter, sprinkle lemon juice and parsley, then serve in the shell.