The singer, 35, showed off her toned tummy and thighs in denim shorts, a chambray shirt and red bikini top while lounging outside with her husband Eric Johnson in a photo she shared to Instagram on Sunday.
“Happy Valentines Day #thisJohnsonisgettinIt,” Simpson captioned the photo.
Simpson credits her sexy body-after-baby to Weight Watchers – for which she was a spokesperson – and regular workout sessions.
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“I work out five days a week: three days with a trainer, doing a mix of strength training and cardio, and then I do cardio on my own the other two days,” she told InStyle last year.
“Having two kids back-to-back was hard on my body,” she said.