The singer took to Instagram on Friday to share a sweet video of himself playing "Kiss Monster" with the little girl.
In the video, little Willa sits on Akins' lap on the porch swing before Rhett approaches, announcing that "The Kiss Monster has arrived, and he needs his kisses!" Willa adorably squeals and protests.
In May, Rhett and his wife adopted Willa from Uganda after a year-long process. The family has spent time bonding in recent weeks with Rhett having cleared his schedule for the arrival of the couple's first biological child due August 8, taking some time at home ahead of the Sept. 8 release of his new album, Life Changes.
The couple are confident that Willa will be a great big sister, though Rhett told Taste of Country that he's not sure the toddler completely understands she's about to get a sister.
"I don't think she fully knows what it means that Lauren's pregnant, or that she's gonna have a sister, but I think once our new child is born, I think Willa is gonna really be her rock and her big sister."