Stefani's ex-husband Rossdale, 55, also shared some sweet shots with his son on his Instagram Stories. There were several throwback shots of Apollo as a young child and one of the cutie in present day where his dad is giving him a kiss on the cheek.
Shelton proposed to Stefani this past fall after five years of dating. The 44-year-old country singer knows that Stefani and her three sons, Kingston, 14, Zuma, 12, and Apollo, are a packaged deal.
"I take it very serious. But I also have a blast with it, I'm not gonna lie," Shelton shared earlier this month during a radio interview. "I don't take it so serious that I'm not enjoying this time because I really am, especially now that we're five years into this thing. I can't imagine my life without these kids now."