The Bush frontman shared a close-up image of his youngest child with a blue filter on it. In the photo, the six-year-old looked a little forlorn but Gavin captioned it: "The deepest love."
His followers commented with blue heart emojis and called him "adorable" and "the cutest" but some found the image scary.
WATCH: Gwen Stefani's boyfriend Blake Shelton 'jealous' after she receives special gift
"This is creepy," wrote one, while another said: "He looks so sad… or maybe intense like his dad."
Just the day before Apollo’s mum shared the cutest selfie with her son who looks like both his parents.
Gwen, 51, and Gavin, 54, share three boys, Apollo, Kingston, 14, and Zuma, twelve.
Fans weren't sure about Gavin's photo of Apollo
They’ve been successful co-parenting for years and over the COVID-19 lockdown they continued to manage their time with their children.
The boys spent a significant amount of time with their mum and her boyfriend, Blake Shelton, 44, at their Oklahoma ranch but recently returned to Los Angeles where Gavin also lives.
He maintains a strong bond with his kids and prides himself on being the best dad he can be.
Gwen's selfie with Apollo was adorable
The musician told People magazine that he’s always looking for ways "to be a better father" and that over the last few years he’s learned a lot about parenting.
It also helps he thinks his children are pretty fun to be around.
"My kids are really funny and cool, and we have such a good time together,” he said. "But I constantly strive to be a better father. I am lucky that my life is so great."
Gwen and Gavin’s oldest son, Kington, feels very strongly about his relationship with his dad and during an Instagram Q&A he was asked what it’s like having a rocker as a father and he said: "Could not ask for a better dad I love him so much."
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