A rep for the Alaskan tabloid figure confirmed the news on Tuesday.
The couple has been dating since December 2010.
Johnston’s new romance follows an epic on-again, off-again relationship with Palin, the daughter of onetime Vice Presidential candidate Sarah Palin.
Their son, Tripp, was born in 2008.
Johnston was recently “honored” byForbes as one of the Most Overexposed Celebrities in America.