Gwen Stefani's Kids 'Adore' Her New Boyfriend Blake Shelton
12/21/2015 AT 03:45 PM EST
"Blake loves kids and has been having a lot of fun when he spends time with Gwen's kids," says a source close to the couple about Shelton's bond with Stefani's sons (with ex Gavin Rossdale) – Kingston, 9, Zuma, 7, and Apollo, 22 months. "They adore him."
Since stepping out as an official couple in November, The Voice coaches "have spent a lot of time together and with her family," says the source.
But while the two have become more serious (Shelton recently took Stefani back home to Oklahoma to meet his mom, sources confirm), they're still taking things one step at a time.
"They're just having fun and enjoying each other," says the source. "There's no pressure. They've been able to support and relate to each other and have gotten through a very difficult and now triumphant time in their lives."
For much more on the couple, pick up the latest issue of PEOPLE, on newsstands Monday.