Pregnant Kim Zolciak bares her baby bump

Real Housewives of Atlanta star Kim Zolciak is proudly showing off her growing and glowing pregnancy. In a bikini, no less!

Zolciak, 35, is expecting twins.

On Saturday, she shared an Instagram selfie, with the caption: "Going swimming with the kiddos! The pool makes me feel so much lighter! This belly ?? #twins #excited#blessed #nofilter."

Zolciak told E! News last month that she was "shocked" to learn she was expecting twins. "I had no idea. It was a natural conception, but twins do run in the family, so I guess I shouldn't have been surprised."

The reality star will be mom to six kids. She has four children — two from a previous relationship (Brielle, 16, and Ariana, 11) and two sons with Atlanta Falcons player Kroy Biermann (Kroy Jagger, Jr., 2, and Kash, 1).