Bring a pot of salted water to boil and cook the pasta until al dente.  Cut and seed the lemons.  Put the garlic and the parsley with the lemons in a food processor and pulse until chopped.  Melt the butter in a saute pan over medium low heat and add the garlic, lemon, parsley combination and the seafood stock.  Stir to combine.  Drain the pasta and add to the sauce with the shrimp.  Toss until the shrimp is just warmed, being careful not to over cook it.  Serve with hot crusty bread and more butter.