The Brazilian model, 41, started dating the How To Lose A Guy in 10 Days star in 2006. The couple married six years later.
Things, however, were a little tense between her and his mother at the beginning, Camila said during a recent appearance on the “Biscuits and Jam” podcast by Southern Living magazine.
Camila recalled: “She did all these things when I first came in the picture, right? She was really testing me. I mean, really testing me.
“She would call me by all of Matthew’s ex-girlfriends’ names, she would start speaking Spanish with me in a very broken way, kind of putting [me] down a bit. I mean, all kinds of stuff.”
Determined not to let McCabe rile her, Camila said she invited her future mother-in-law to go with her on a work trip to Istanbul.
Initially, McCabe wouldn’t give up either. Camila recalled: “The whole way there, the whole plane ride to Istanbul, she was telling me all these stories and putting all these things in my head.”
It was on the third day of the trip that the designer realised that McCabe was “full of s***”, she joked. “So I just flip it on her and brought my spicy Brazilian, Latin side, and I let her have it.”
“So I went back at her, and we had it back and forth, back and forth. And then at the end, she just looked at me and she was like, ‘OK. Now you’re in’.”
Camila and McCabe’s relationship took a turn for the better after the model realised that the older woman had wanted her to “fight back”.
“And then, from that day on, that night on, we have the most amazing relationship, and I have so much respect for her. She has so much respect for me,” Camila said, adding that while things between them can be “tricky” at times, they are able to get through with “a good laugh and a joke”.
Camila and Matthew married in a three-day celebration at their home in Austin, Texas, on 9 June 2012.
Their wedding was attended by 120 guests, who included Reese Witherspoon and Woody Harrelson. Their children, Levi, 15, and Vida, 13, participated in the ceremony as ring bearer and flower girl.
Speaking to People, Camila said the children seemed “to understand what we are doing on a spiritual level”.
Matthew added: “We decided to embrace the ritual of marriage as a opportunity and adventure we’ll take together.”
The couple welcomed son Levi in 2008 and daughter Vida in 2010. Their third child, Livingston, was born at the end of 2012.
Earlier this year, Camila and Matthew gifted 15-year-old Levi with social media accounts for his birthday, but opened up about feeling “nervous” about their son being online.
They revealed that they had been “talking about it for three years now”, but were confident that the teenager “knows who he is”.
“i think he can handle it,” Matthew said in a joint Instagram video with Camila. “He has a great story to tell, to share.
“I want to let all of y’all know you’re getting a very cool and respectful young man, Levi McConaughey is coming at you, and I hope you can all do your best to treat him the same way.”