Gwen Stefani is said to be completely smitten with her boyfriend, Blake Shelton.

According to a new report, the 40-year-old country singer has been teaching Stefani's oldest sons, 11-year-old Kingston and nine-year-old Zuma, how to play the guitar -- and melting the "Used To Love You" singer's heart in the process.

“Blake has really taken to all of Gwen’s kids and loves to share his passions with them,” an insider revealed to Hollywood Life on September 19. “Besides Gwen, nothing is as dear to Blake as his country music, so to share his own country style of guitar meant a lot to him. It seemed to mean even more to Gwen, though — she was brought to tears as she saw her boys learning from her man.”

Throughout Stefani and Shelton's romance, her sons, including three-year-old Apollo, have grown extremely close to her boyfriend.

“They’ve really fallen in love with Blake and have a strong bond with him,” the source dished. “They are very much attached to Blake and hope he is around for a long time.”

As for whats next for the couple, a source last year told People magazine that an engagement could come at any moment.

“They are not engaged yet, everyone is expecting it to happen at some point, though,” the source said at the time. “It seems the timing [for an engagement] just hasn’t been right, but Gwen is very, very happy with Blake. She always acts giddy when she talks about Blake.”

“There are no immediate plans for their future, but it’s a serious relationship,” another insider added.

“Their relationship is almost too good to be true,” said a Stefani source. “They are very much alike and really have a very special relationship. All the things that need to work out for two people to merge lives have worked out.”