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Matthew McConaughey and Camila Alves welcomed their third child five months ago, and today, they told ABC News that they were in the middle of the first weekend away from their kids since his birth.

"It's very relaxing, exciting," Alves said at the Veuve Clicquot Polo Classic. "I got off the plane and was like, 'No car seats! No strollers!'"

"We noticed on the plane: 'Where is everybody?'" said McConaughey, who also told reporters that he's gained back much of the weight he lost for "Dallas Buyer's Club." He said he'd gained the weight back by just increasing the portions of his already healthy diet.

The couple, who were there on behalf of their Keep Livin Foundation, a charity dedicated to empowering high school students to live active and healthy lives, were ready to kick back - but their minds were clearly with their kids, Levi, 4, Vida 3, and baby Livingston.

"Right now there's a whole lot of signs of me in all of them," McConaughey said. "It's a colorful house that's for sure! And talk about whose personalities: One thing you learn when you're a parent that I didn't know as much beforehand is how much DNA … as soon as they're born they are who they are. You can shape them, but they're very unique, different from each other immediately."

But his little girl has her dad wrapped around her finger, he said: "That's a constant honeymoon!"

Alves said that three kids is work, too.

"It's not that it's tougher - it's just that I had my systems down with two kids and now with three I'm still learning," she said of her little ones, who are "into everything."

"I'm taking tips," she said. "I'm still working on the systems that work for three, but we'll get there!"