Angelina Jolie, Brad Pitt Have Valentine’s Day Date With Twins Vivienne and Knox — at Natural History Museum

Brad Pitt and Angelina Jolie Jason Merritt/Getty

Nothing says romance like dinosaur bones! Brad Pitt and Angelina Jolie kicked off Valentine’s Day 2013 with their youngest kids, 4-year-old twins Vivienne and Knox — heading to the Natural History Museum in downtown Los Angeles late Thursday morning.

With a bodyguard in tow, the foursome arrived at the museum — parking in the standard parking lot and with no special VIP treatment — and went straight to the dinosaur hall, a witness tells Us Weekly of the “excited” group.

As Jolie, 37, held hands with Vivienne, Pitt, 49, held onto to Knox. “Brad was walking around reading to Knox and explaining things to him,” the observer notes. The A-list family — minus Maddox, 12, Pax, 8, Zahara, 7, and Shiloh, 6 — paid particular attention the “hands-on stuff” at the discovery center upstairs, where the kids played with fossils and inspected items with microscopes.

knox and vivienne
Knox and Vivienne Jolie-Pitt (2)

“Vivienne loved the butterflies and Knox was interested in the dinosaurs and giant spiders,” the witness adds. “Brad and Angelina stood back at one point and let the kids play. They were smiling and really enjoying the day — you can tell they love watching their kids learn.”

Engaged since last spring, the parents reportedly had a more grown-up date later that night with dinner at the Roosevelt Hotel. As Us Weekly revealed on Thursday surprised his love of nearly eight years with a gag gift: Breath mints!

“It is sort of a joke — and not,” a source close to the superstar couple tells Us Weekly of the vegan, gluten-free, sugar-free product, called EatWhatever. “He always teases her that she has bad breath . . . he’ll also get her something more serious.”

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