JENNIFER Aniston is very close to her best friend, Courtney Cox Arquette – and she’s about to get even closer. Aniston is guest-starring in Arquette’s FX show, “Dirt,” playing her archenemy, a rival tabloid editor. But even better, according to Michael Ausiello of TVGuide.com, “Aniston’s character is a lesbian. What’s more, she won’t just mouth off to Cox’s tightly wound counterpart; she’s going to share a lip lock with her.” That should pump up the ratings. Reps for Aniston and Cox didn’t return e-mails.