I am 1P and next week my family and I are flying on LH from IAD to MUC using miles. According to the Mileage Plus rules, 1P passengers have access to lounges for international travel. Does LH have a lounge at IAD? Will I have any problem since I am using ff tickets? Will I have any problem bringing my family into the lounge with me?

Also, on the return I leave from Frankfurt on UA. I assume I will have the same privledges in Frankfurt.