The singers have led largely separate lives since they wed in 2011 because Lambert is constantly touring and running her clothing store in Oklahoma, while Shelton spends a lot of his time filming hit U.S. Tv talent show The Voice.
Due to the distance, the couple has been plagued by break-up rumours for months, however The House That Built Me hitmaker denies the speculation and insists they've implemented a few rules to keep their relationship going strong.
She tells Us Weekly magazine, "Either one of us can always look at each other's phone (sic), and we know each other's passcode. I don't have to snoop any more. It just takes the question out of the marriage. I (also) like to check his direct messages (on Twitter.com)."
The musicians have also limited their time apart to 14 days, adding, "After that, you start building up walls, and then it's too hard to get to know each other, you know?"
And they always make time to reconnect, whether or not they're in the same state: "Me and Blake are buddies... We talk at least once a day, and we text a lot... (When we're home) we watch movies and sit on the porch and drink beer and cook burgers. It's important for married couples to be just friends too. We really love each other and have a real marriage."