Pregnant mom's ultrasound reveals twin babies 'kissing' inside womb

— -- A sonogram image that appears to show a pair of twins sharing a kiss inside the womb is melting their parents' hearts.

The moment was photographed during first-time mom Carissa Gill’s 24-week ultrasound.

"In the 2-D ultrasound that I see in the doctor's office, they're never that close together -- just seeing them face to face, it was a big shock," Gill told ABC News. "You can see their mouths open and closing. It started when Bella was kissing Callie's cheek. Two weeks before that they were kicking each other."

Gill 22, had the ultrasound done on April 4 at Fetal Vision Imaging in Levittown, Pennsylvania.

"Congratulations Carissa and Randy with your kissing twins!" the company wrote on Instagram. "Thank you for coming to Fetal Vision, we hope you enjoyed your experience with us!"

The facility offers parents an opportunity to see their baby in 3-D or 4-D.

"Seeing that ultrasound like that was priceless to me," dad Randy Good told ABC News.

Gill and Good's identical twin girls, who will be named Isabella and Callie, are due on July 26. Mom and dad said they are looking forward to sharing the photo with their daughters in the future.

"I don't know if they're going to love each other as much as they do when they are in the womb, but we can use it as blackmail later on," Gill joked.