The couple has been together for four years, and rumours have swirled about engagements and trying for a baby.
According to People, Blake and Gwen are serious about their relationship, but Gwen hopes to have a church ceremony if she were to marry Blake.
Gwen was married to Gavin Rossdale for 13 years before they separated in 2015, and Blake was married to Miranda Lambert before they filed for divorce the same year.
The Roman Catholic Church, of which Gwen is a member, does not allow remarriage after a divorce unless the previous marriage has been annulled. The annulment process can be long and certain requirements must be met.
The "Rich Girl" singer's divorce from Gavin was finalized in 2016, but that’s different from getting it annulled.
Whether Blake and Gwen eventually have a church ceremony or not, the couple is still very committed to each other. The Voice coaches frequently sing each other’s praises and walk the red carpet together. Sources report their families are close and the country singer is like a father figure to Gwen and Gavin’s three sons, Kingston, Zuma and Apollo.
The long-time couple has also been working together professionally! Most recently, they collaborated on a new love song entitled “Nobody But You,” which is featured on Blake’s new album Fully Loaded: God's Country, which drops Dec. 13.