While promoting their latest film, The Whole Truth, on Monday, the co-stars got candid on why they choose to keep their private lives out of the spotlight.
"Don't you think a little mystery is a good idea?" Zellweger, 47, asked ET's Deidre Behar. "I might just be lazy and think that it's too much of a commitment to post things."
"I try to call my mom during the day and answer the row of emails that have come in," she added. "That seems like enough for me, and I don't know that tweeting is always a safe bet, depending on how emotional your day is."
For Reeves, it's a "privacy" thing.
"[Privacy] is important to me," the 52-year-old actor explained. "And yeah, I don't really have anything to say about anything!"
Although Reeves and Zellweger can control what they personally post on the Internet, they can't control what other people or the media put up about them. So how have they managed decades of fame?
"I just use alcohol," Reeves joked.
Zellweger chimed in, saying, "Yeah, most of it is really unimportant and unnecessary and makes a person's life way more interesting and colorful than it is in truth."
"I guess it depends on the day and circumstances and what becomes necessary," she continued.
Social media aside, the two also gushed about what it was like working together on the Courtney Hunt-directed drama, which is in theaters and on demand on Friday.
"I've been told by many of our mutual friends that he's the nicest guy in the world," Zellweger dished. "And that, by the way, is his reputation internationally."
Reeves echoed her sweet sentiments, telling ET, "Just being a fan of [Zellweger's] work and to actually see it in person and have the honor of playing together to tell a story together was just like, 'Oh my gosh, you are really, really, really good!'"
Hear more from Zellweger and Reeves' exclusive interview with ET in the video below.