I agree wearing thong underwear should be an easy thing no matter where you are. Thong swimwear will depend on your comfort level with your family, their acceptance and the environment your in. The lake is a great place for a thong.
I know I will be visiting family this weekend. The only underwear I’ll have packed will be thongs. I plan some beach time, once again wearing my thong. I’ll pack a mesh pair of shorts and a rio back suit as well in case their is a need, but my plan is to sun my buns on a big open beach.