Lisa Kudrow's timing was impeccable. The very night of the May 6 Manhattan premiere of her new movie, The Opposite of Sex, in which she plays a gay man's sister who becomes pregnant by Lyle Lovett, the Friends actress was in labor. Early the next morning, with her husband, French-born ad exec Michel Stern, 40, and her mother, Nedra, 64, by her side at an L.A. hospital, Kudrow, 34, gave birth to Julian Murray Stern, a healthy, 6 lb. 12 oz. boy. "I'm really happy that Lisa's baby is here," castmate Matt LeBlanc (Joey) told PEOPLE. "And I was just kidding about offering to babysit."

"I'm very relieved," jokes Matthew Perry. "I thought Lisa was just getting fat." (Right. And that would be Chandler Bing you're channeling?) On the May 7 season finale of Friends, Kudrow's ditsy character, Phoebe (she's the surrogate mother for Alice, her half-brother Frank Jr.'s wife), was still pregnant with triplets and won't give birth till the show's fifth season next fall.

Friends executive producer Marta Kauffman says that Kudrow "had a glorious pregnancy. People on the set couldn't keep their hands off her belly, but she was always a good sport about it." A laid-back good sport. "She was the most relaxed expectant mother I've ever seen," says Don Roos, who directed Kudrow in The Opposite of Sex. "She never complained one bit." On the phone shortly after the delivery, he adds, Kudrow "didn't sound tired. She was really perky." And weepy with joy. "She keeps looking at [the baby]," says Roos, "and wants to cry."