Jennifer Aniston will be co-hosting Ellen this week, and apparently she was a little nervous about the gig. So who does she turn to her for advice? Her former Friend, Matthew Perry! Watch Jen stop by Matthew's house for pointers (and Friends jokes), only to find a few exciting surprise visitors. Later in the show, Ellen puts Jen in the hot seat about whether or not she'd be up for an even bigger Friends reunion, and Portia de Rossi stops by to talk about Ellen's love for moving and real estate. The episode airs Wednesday, but watch the clip now!