Thomas Rhett and his wife marked a very special relationship milestone with a night out on the town just before Christmas.

The "Marry Me" singer and wife Lauren took in a special performance from the award-winning Nashville Symphony on Thursday night (Dec. 21), and she turned to Instagram to share a smiling selfie with her husband, explaining that it wasn't just any old date night.

"Christmas date night at the Nashville symphony listening to the orchestra play the live music while watching Home Alone ... sooooo magical," she writes to accompany the picture, adding, "side note-we got engaged 6 years ago tonight ... love you TR. #itsthemostwonderfultimeoftheyear."

The couple have plenty to celebrate this Christmas. In May, they brought their adopted daughter, Willa Gray, home from Uganda, and in August they welcomed their biological daughter, Ada James. Rhett says he and Lauren are eagerly looking forward to their first Christmas with their kids.

“You know, growing up, waiting for Christmas felt like you were sitting there waiting for six years," he observes. "And now that we have kids, I do think that little anxious feeling of ‘God it’s gonna take me forever to fall asleep tonight’ is gonna be back — because we know that that’s what Willa and Ada are thinking about. So, it’ll be fun."

Rhett has also seen huge career success this year. His current album, Life Changes, became his first No. 1 album on the all-genre Billboard 200, and also reached No. 1 on the Billboard Top Country Albums chart. The album has scored two chart-topping singles with "Craving You," which features Maren Morris, and "Unforgettable." Life Changes is also nominated for Best Country Album in the 2018 Grammy Awards.

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