The Doctrine of the Two Jays

We had some friends visiting us at the beach today, Jay and Jim Greenan. They have been friends of the Smiths for many years. I never met Jim (Jay's twin) until yesterday. After some time at the beach Laney came up to me and whispered a question, "Are there two Jays?" She had never encountered twins before. Jim was wearing a tee shirt that said "I'm the evil twin." At first, Laney was calling them "Jay one" and "Jay two."