Sean Lowe posted this adorable picture of him, fiance Catherine Giudici, and his nephew and niece hanging in the pool on July 4. Credit: courtesy of Sean Lowe

Catherine Giudici got in some "Auntie Catherine" practice on Thursday, July 4 -- enjoying pool time with fiance Sean Lowe and his niece, Kensington, and nephew, Smith.

In a photo captured on Lowe's Instagram, the buff bachelor, 29, is seen with his nephew on his shoulders, while Giudici, 27, happily poses with Kensington, wearing a black bathing suit. "Happy 4th of July!" he captioned the sweet family picture.

Indeed, the pair have been happier than ever since the Dancing With the Stars contestant asked the Seattle native to marry him during a romantic proposal in Thailand on the Bachelor season finale back in March. 

After the proposal, Sean's older sister, Shay Shull, (mom to Kensington and Smith) blogged on her site how excited she was for her brother and Giudici. "I'm praying for my brother and his new relationship," she wrote. "I'm praying for him to always trust in the Lord with all of his heart and live a life that pleases Him."

As Us Weekly reports in its July 15 issue, the newly-engaged couple are not concentrating on wedding plans just yet. 

"We want to enjoy the summer," Lowe, a Texas native, explains to Us. Adds Giudici, a graphic designer, of the nuptials, which will be televised for ABC: "We want a beautiful backdrop to exchange our vows."