Heidi Klum & Martin Kirsten: Beach Day with the Kids!

Heidi Klum and her boyfriend Martin Kirsten watch as her kids Leni, Henry, Johan, and Lou build a sandcastle on the beach on Sunday (March 10) in Malibu, Calif.

Earlier in the day, the 39-year-old Project Runway host and her beau dropped the kids off at a gym before grabbing coffee together in Los Angeles.

PHOTOS: Check out the latest pics of Heidi Klum

The day before, Heidi and Martin sat on the sidelines of the kids’ soccer game at a park in Brentwood.

35+ pictures of Heidi Klum and her family out and about…