Joe Termini for Roxy

Hailey Baldwin is NOT a fan of social media -- to the point where she even deletes Instagram sometimes, she admits.

The model would seem to have nothing to worry about, with a Roxy-worth bod as she shows off in the swimwear line's new campaign ... but EVERYONE'S got haters on the 'Gram, apparently. And when you're Mrs. Bieber, there are plenty of jealous people to post negative comments that would send some ladies off the deep end -- but not Hailey.

Hails tells Cosmo: "I’ve found that I got to a place where I don’t read the comments." She's realized it's just not worth it: "You still care to a certain extent. You really have to train your brain to be like, ‘Okay, why do I even care? I don’t know these people, they don’t know me, they’re not a part of my life or my relationship.’ People can just be mean, and I feel like if you don’t want it to get to you, then don’t read it and allow it to affect your soul."

Mrs. Bieber also tells the mag she sometimes takes a complete break from social media: "Sometimes I delete Instagram for a couple days at a time, which is really nice. I’ve done that when I’ve felt like I really couldn’t handle what people were saying or it was like what I was looking at was unavoidable."

Hailey's making the rounds promoting her new line with Roxy, along with her BFF professional surfer Kelia Moniz. The lovely ladies posed for Roxy and it was totally organic -- they're best buds AND Kelia's hubby Joe Termini shot the campaign. Moniz tells Cosmo she's amazed at her friend's composure, being in the spotlight as she is: "Watching the way this girl handles her life under the microscope of literally the entire universe...She holds the standard of who she is as an individual so high. She’s the same consistent human being, always. And she goes through all the craziness of her life so positively and strongly and doesn’t let all the outside comments and all the things of life hinder her spirit, and it’s really really inspiring to see."

We think Justin's inspired by it as well -- in fact, we suspect part of the reason he married Hailey was for the stability she brings to his life. As he battles depression and anxiety, Baldwin is always there for him and is a calming influence. Just see how relaxed and ADORABLE the pair was earlier this week at the beach in our EXCLUSIVE PHOTO GALLERY!