The pair talked about the challenges of being in a public relationship during an interview on the Mom star's Anna Faris Is Unqualified podcast.
Nocturnal Animals actress Fisher, who's married to Borat star Sacha Baron Cohen, said that she doesn't like to talk about her husband or their kids in interviews.
"Chris and I, we talk about this a lot," Faris, 40, admitted. "We grapple with a lot of the ideas of being a public couple."
Faris explained that they were tested about a year ago when "there were some tabloid rumors about strain in our relationship."
She tried to ignore it, but "I just remember feeling so hurt in a way that bothered me, because I didn't want to think of myself as somebody who could be affected by … tabloid s--t."
When Fisher, 40, asked her what hurt the most and made her feel the most vulnerable, Faris explained that "it was a combination of things."
"I take pride in how great my relationship is with Chris, but having said that, of course, in this crazy world where he's off doing movies and I'm in L.A. raising our child, of course I'm going to feel vulnerable, like any normal human would."
Even though she knew the rumors weren't true, Faris admitted, "It made me feel incredibly insecure."
Faris and Pratt, 37, met in 2007, when they costarred in the movie Take Me Home Tonight and married two years later. They are the parents to a son, Jack, 4.
The former House Bunny star spoke out in August 2015 about the infidelity rumors, describing it as "weirdly stinging."
"It's been a little devastating because for us, it's like, What the heck?" she said. "This has been blindsiding to us. We have an incredible relationship."