Although they weren't pictured together, both posted separate photos on their Instagram accounts depicting identical scenes.
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Formula One champion Lewis was the first to share a picture, which showed him sat on a snowmobile with the sun setting in the background.
"Great way to enter the year....snowmobiling with God's view," the 28-year-old racing driver wrote. "Truly am blessed to have a great family with me. #onelove"
X Factor judge Nicole followed suit a couple of hours later by uploading her snap and a similarly upbeat caption.
What better way to kick off 2014 in God's Country!," the former Pussycat Doll wrote. "Praying and snow mobiling! #Everything! #Glorious!"
Neither Nicole or Lewis directly addressed them being back together but there was further proof that they saw in 2014 together when they posted pictures of their New Year's Eve celebrations alongside Alicia Keys and her husband Swizz Beatz.
Hawaii-born Nicole, 35, posted a glamorous shot of herself alongside Alicia and another friend while Lewis shared a picture of himself the singer's hip hop artist husband.
Lewis's Instagram account also featured photos of his brother and mentions of other members of the Hamilton family suggesting that Nicole had joined them on their family break.
After splitting in July, reports emerged that they spent seven-and-a-half hours in each other's company during a secret rendezvous at a London hotel.
The pair had a famously on-off relationship during the five years they were together, splitting temporarily in 2011 and 2010.
They met at the MTV European Music Awards in 2007 and two made their relationship public six months later at the Monaco Grand Prix.