A young man sporting shoulder-length hair, shorts and a turquoise, tie-dyed T-shirt holds the bottle to the baby's mouth and rocks her gently.

"Let's try it one more time," he says softly to the 8-month-old girl. He smiles as she begins feeding.

The 21-year-old man isn't a fledgling father or uncle. He's a live-in nanny to a family of five in northern Howard County. Move over, Mr. Belvedere. Make way, Mr. French. Meet Matt Stephen, of Catonsville, a nanny of the '90s.

"It's not a terribly big deal," Stephen said.

But Stephen's help, provided to the family by a Columbia nanny service, is a big deal to Michael and Robin Lake and their three children. Stephen helps feed, dress and entertain the Lakes' infant, Amelia; 3-year-old daughter, Hannah; and 7-year-old son, Cal. Although Stephen has been on the job for only a few weeks, he's almost like one of the family, Robin Lake said.

"He's very calm. He's very happy. He seems to fit right in," she said.

Stephen, a former student at the University of Maryland at Baltimore, lives during the week in an apartment in the basement of the Lakes' home near Sykesville. His workdays begin at 7 a.m. and generally last until 6 or 7 p.m. The "morning rush hour" is the busiest, Stephen said. "I get Cal ready for school . . . change Amelia and get her breakfast. Things calm down a bit after they go to school."

Cal, sprawled on a rug in the Lakes' living room, radiates affection for his combination babysitter and surrogate older brother. Cal, who has cerebral palsy and communicates "yes" and "no" by turns of his head, grins when Stephen deciphers his request to play the board game Bed Bug with him.

"We weren't looking for a man or woman," Robin Lake said. "We were looking for how well someone interacted with my children . . . and Cal liked him." At dinner time, Stephen calms the restless children with games and helps with chores.

Being a nanny came easy to him, Stephen said: "I grew up with seven children. And when I was in high school, my mom had two more kids."

A Choice Nanny, the referral service that matched Stephen and the Lakes, began training men for its male caregiver program last summer, aided by a man who was a longtime nanny to "a very prominent family within the entertainment industry," said Dorothy Carroll, director of operations and training. Though the business has placed more than 1,200 female nannies in the Columbia area, Stephen is the first man to be matched with a family.

Requests for live-in nannies from families and single mothers are increasing as crime, drugs and social changes continue to weaken the traditional family structure, Carroll said. Many families want role models as much as babysitters for their kids, she said.

The desire for a man in the house led the business recently to launch a service called "Nanny Guard," which provides families with combination nanny-body guards. Jack Smith, a West Friendship resident who was a Secret Service agent for the White House, serves as a consultant to the service.

The businesss has 24 branches from Ohio to Florida, including ones in Towson, Bethesda, Olney, Annapolis and Vienna.

Changing attitudes, Carroll said, also played a part in the decision to market male nannies: "Young men feel more free today to challenge traditional roles."