Kourtney Kardashian shows off baby bump in new bikini photo

SOUTHAMPTON, N.Y., July 8 (UPI) -- Kourtney Kardashian took to Instagram to show off her baby bump.

The 35-year-old reality star posted a snapshot of daughter Penelope cuddling up to her future sibling. Kardashian sports a gold bikini in the picture, and both mom and daughter seem to be enjoying the sun.

Kardashian confirmed her pregnancy in June on the season nine premiere of Keeping Up with the Kardashians. She and partner Scott Disick are already parents to Mason, age 4 and Penelope, age 2. The new baby is due in December, and a source tells Us Weekly Kardashian and Disick don't know the gender yet. "They just want the baby to be healthy," the insider says.

Keeping Up with the Kardashians airs on E! Sundays at 9 p.m. ET.