Kate Hudson’s four-year-old son Ryder went to a Father’s Day brunch with her new beau Lance Armstrong — and dad Chris Robinson.

With their kids in tow, Hudson and Armstrong split into two cabs for the ride from the actress’ New York City home to Brooklyn restaurant Frankie’s 457.

“There was a boys’ cab and a girls’ cab,” an onlooker tells Joynews. “Ryder went with Lance.

“He was very comfortable with Lance,” the onlooker adds. “He ran right towards him!”

The actress and the cyclist — who were also spotted in Toronto over the weekend at a charity bike race — put the focus of Father’s Day on their young kids. (Armstrong has a son, Luke, 8, and twin daughters Isabelle and Grace, 6, with ex-wife Kristin, whom he split from in 2003.)

“They were corralling all these kids together,” the eyewitness says. “It was really about the kids.”

Ten minutes after arriving in Brooklyn, two more guests showed up: Hudson’s ex Chris Robinson and his girlfriend.

“They all celebrated Father’s Day together,” the witness tells Us.

The big group left after about two hours, at 12:30 p.m.

Hudson has played coy about her two-month relationship with Armstrong. “You should ask him [if we're dating],” she told Barbara Walters (Watch here).

Tell Us: Do you think it’s too early for Kate and Lance to introduce their kids?