If you are that uncomfortable with being nude or showing your penis, then don;t go. If you are allowed to wear swim trunks then wear swim trunks. A speedo or thong just won;t hide much. I am 8.5" soft, and it's not easy to conceal in a speedo, thong, jock, or even just a regular pair of underwear. Be proud of what you were given. If you go nude, you'll be the envy of the group, men will want to be like you, and the women will just be extra friendly.