Julia Roberts is getting honest about the hurtful nature of social media.

The 50-year-old actress opens up to Oprah Winfrey in a new interview for Harper's Bazaar, and talks about joining Instagram in June.

Roberts says her kids with husband Danny Moder -- 13-year-old twins Hazel and Phinnaeus and 11-year-old Henry -- convinced her to do it, and although she blocks comments unless they are from one of the 18 people she follows, she did recently receive a lot of hate on her niece Emma Roberts' Instagram.

The 27-year-old "Scream Queens" actress shared a makeup-free photo of the two playing cards, and Roberts was shocked when the picture received plenty of nasty comments about her appearance.

"Something did happen recently on my niece Emma’s Instagram that I think taught me a lot about what it’s like being a young person in today’s society," Roberts says.

"One weekend morning Emma slept over, and we got up and were having tea and playing cards and having this beautiful morning, and then a couple of days later she posted a picture of us. And the number of people who felt absolutely required to talk about how terrible I looked in the picture -- that I’m not aging well, that I look like a man, why would she even post a picture like this when I look that terrible!"

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"And I was amazed at how that made me feel," she continues. "I’m a 50-year-old woman and I know who I am, and still my feelings got hurt. I was sad that people couldn’t see the point of it, the sweetness of it, the absolute shining joy of that photo. I thought, 'What if I was 15?'"

However, the experience did teach Roberts about living in a different time than her children.

"I was so happy that happened because I had this whole new glimpse into a way of living that I didn’t get at all," she explains. "You have to go through things to understand them, and this was just a little paper cut of what can really go on with social media."

Julia Roberts covers Harper's Bazaar's November issue. (Alexi Lubomirski)

Roberts also admits to Winfrey that she's affected by tabloid rumors when it comes to her 16-year marriage to Moder.

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"Sometimes we are in the grocery store and I won’t even know something is out, but we’ll see a tabloid and we’ll all be standing there like, 'Oh, that’s uncomfortable. This is really uncomfortable,'" she shares.

"It can still hurt my feelings, because I’m so proud of my marriage. We just celebrated being married for 16 years this Fourth of July, and there’s so much happiness wrapped up in what we’ve found together. What I like is when they write, 'the $150 million divorce,' and then a week later a different tabloid says, 'the $275 million divorce.' I’m like, 'Well, somebody got a paycheck in the last week. This is getting good.'”

Later, Roberts talks about how her kids deal with her incredible fame. The Oscar-winning actress says she's unsure if they fully grasp it.

Julia Roberts covers Harper's Bazaar's November issue. (Alexi Lubomirski)

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"I don’t think they will ever have a true sense of that," she notes. "I think I told you once when they were starting to figure it out, it was like, 'You’re famous?' And I said, 'I think a lot of people might have seen the movie that I’m in or might know who I am.' Maybe an hour goes by. 'Are you more famous than Taylor Swift?'"

But she is open to her children seeing a few of her most beloved films -- just not "Pretty Woman."

"No," she says to Winfrey about maybe one day sitting them down to see the 1990 film that launched her into superstardom. "Imagine a day that we all sit down and maybe watch 'My Best Friend’s Wedding.' Or maybe -- 'Steel Magnolias.' Oh, my God. Yes, we could do that."