Jenelle Evans shares a snap of herself in a bikini less than one week after giving birth. Credit: Courtesy of Jenelle Evans

And she's back! Teen Mom 2 star Jenelle Evans rocked a bikini on July 5, less than one week after giving birth to her second son, Kaiser, on June 30.

Via Instagram, the MTV reality star posted a photo of herself soaking up the sun in a purple printed bikini with the simple caption of a heart emoji.

Evans enjoyed one-on-one time with her eldest son Jace, 5, while at the beach. The 22-year-old shared a snap that same day of her adorable toddler, whom she shares with ex Andrew Lewis, wrapped in a beach towel with the caption: "Early this morning. Got to enjoy one on one time with Jace for a couple of hours."

While pregnant with her second son, the brunette was proud to reveal she'd only gained about 18 pounds, tweeting at eight months pregnant, "Whoaaaaa! I only weigh 128 lbs, 8 months pregnant. Pure baby!"

The mom of two is on the fast-track to losing the baby weight as well. Evans shared a picture on July 6 looking trim in a tight tank top with the caption, "Chillin with Kai in the backseat. Wal-Mart run with the family. #SlimmingDown."

Kaiser is the first child for Evans and her boyfriend Nathan Griffith, who also has a daughter from a previous relationship.