The 43-year-old star has reflected on his romance with his partner, and he claimed being with the 50-year-old singer has made him a much nicer person.
Speaking to 'The Voice' co-star Kelly Clarkson, he told 'Entertainment Tonight': "I don't want to remember what I was like before Gwen, actually.
"I'm a little bit of a jerk to you still. But I was a jerk to everybody... Look how nice I am now!"
And Gwen also got emotional as she revealed how much her own life has changed thanks to their relationship.
She added: "Blake saved my life, everybody knows that.
"Like, we're just having the time of our lives, and we never expected that this late in our lives, so we're just trying to savour every moment together, and just to be back on 'The Voice' as well - not to change the subject - but working together again has been really fun, and I love being here and I love being with him."
The loved up couple - who have been together for four years - are set to duet together on new track 'Nobody But You', which will appear on the country crooner's upcoming new album, 'Fully Loaded: God's Country'.
Blake admitted the track was originally written just for him but he made a last-minute decision to ask his girlfriend to join him in the recording studio.
He recently said in a statement: "This was one of those songs where the more I heard it, the more I fell in love with it.
"I also realised how important it is for me and where I am in my life, and I think that's why [writer] Shane [McAnally] was trying to get it to me.
"It fits my story. I was about to go in and record when I decided that it needed Gwen on it -- because it is our song. I think it's magic."