Christine Quinn could sell a lot more than real estate these days — the “Selling Sunset” star might wanna bottle her post-birth workout regimen, ’cause she hit the beach to show off some tremendous results.

The real estate agent — who’s featured on the Netflix reality series — was on the beach in Taormina, Sicily … cruising the shore with her newborn son, Christian, in hand — who’s just about 3 months old at this point.

Check out the photos … Christine was cradling her baby boy in her arms, and even got into the water with him — holding Christian and an umbrella pretty seamlessly.

Cute mom and son moment, no doubt, but the other takeaway is how good Christine’s looking. She had to have an emergency C-section during delivery in May. Three months later, as they say … baby and mom are doing fine. Really fine!!!

Christine hasn’t been shy about showing off her fitness during her Italian getaway.

The whole fam’s out there — including her hubby, Christian Sr. — and it seems they’re having a ball. Baby Christian probably won’t remember this, but his folks sure will. Enjoy!