I went on a hot spring trip with my nieces whom I hadn't seen in a while. They caught me peeking at them changing and said, "Well then, Uncle, let's take a bath together!" I hadn't bathed with someone in a while, but they noticed my dick was erect and started jerking it off while pretending to wash. Even my niece has grown up and is horny now, so it's okay if we have sex alone in the bathroom.
