"They were so nice," says an onlooker of their Jan. 20 visit to Q Roadhouse and Brewing Co.

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They’re still in the honeymoon phase!

Not long after their intimate Jan. 5 nuptials, Cameron Diaz and Benji Maddien took off for Jackson Hole, Wyoming, to celebrate saying “I do.”

The newlyweds stayed at a luxury cabin at the Shooting Star resort last week, PEOPLE confirms.

Then, on Jan. 20, the pair stepped out for a date night at local restaurant Q Roadhouse and Brewing Co.

“They were so nice and cute together and couldn’t have been more complimentary and polite and cool to all the staff,” an onlooker tells PEOPLE. “Everyone said how great they were.”

Shortly after their Wyoming getaway, Diaz, 42, and Madden, 35, enjoyed a family brunch at the Four Seasons hotel in Beverly Hills with the Good Charlotte rocker’s brother Joel, his wife Nicole Richie and their kids Harlow, 7, and Sparrow, 5.

“Cameron and Benji looked like newlyweds,” a source told PEOPLE at the time of the Jan. 25 outing. “They seemed happy, too.”