Harington, who previously pranked Leslie last April Fools' Day by placing a replica of his head from Game of Thrones in their refrigerator, said Monday that he tricked his wife into thinking her favorite almond milk brand was going out of business.
"She won't drink any other almond milk. So I just wrote an article about how this company that makes her favorite almond milk was going under because of Brexit," the actor said.
The prank backfired on Harington, however, after Leslie used her husband's credit card to bulk order the almond milk.
"So I end up spending 150 quid on almond milk," he continued.
Harington also discussed HBO's upcoming eighth and final season of Game of Thrones which begins on April 14.. "There are definite big moments." the Jon Snow star said.
Harington, 32, and Leslie, also 32, appeared together on Game of Thrones with Leslie portraying Jon Snow's former love interest, Ygritte. The couple tied the knot in June after dating for nearly six years.
Harington recently shared on The Tonight Show how he once wore a Jon Snow costume to Leslie's birthday party.