Lisa Kudrow is sharing a hilarious story from the set of !During her guest appearance on on Wednesday, the 57-year-old actress told host Conan O'Brien that her son, Julian, used to think that her co-star, Jennifer Aniston, was his mom. Kudrow portrayed Phoebe Buffay on the long-running television sitcom, while Aniston played Rachel Green.«I know he hasn't seen every episode.