Bieber and Gomez dated on and off from 2011 to March 2018, according to Fashion Magazine.
In an Instagram story on Thursday that has since been deleted, Baldwin wrote: “You little internet kiddos need to learn how to move on for real. We’re adults that have better things to do than waste time explaining something just so you can stop your delusional fantasies.”
The post, which was captured in a screenshot taken by fans, ended with: “I’m not gonna sit here and let obsessive strangers try to tell me about my own husband, you wanna talk about somebodies [sic] husband then get ur own. G’night!!”
The comments Baldwin was slamming have since been deleted, but the Daily Mail captured several screenshots.
“Can you stop forcing your relationship already… we all know your 2nd best. You always will be and always have been…,” one person reportedly wrote.
Another person commented: “He will leave you one day and he will go to Selenaaaaaaaaaa.”
Someone else said: “You’ll never be @selenagomez never ever.”
Bieber and Baldwin got married at a New York City courthouse in September after a reported 12 weeks of dating.
In March, Bieber also slammed trolls who suggested he wasn’t in love with Baldwin.
“You are NOT in love with Hailey! You only married her to get back at SG plus Hailey sleeps with men like @shawnmendes for fame and she’s racist,” the hateful commenter wrote on a photo Bieber had posted on Instagram.
Bieber took to the comments of his own post to hit back.
"Ur immature the fact that you have an account dedicated to dissing my wife and I is absolutely absurd why would I dedicate my whole life to someone in marriage to get back [at] my ex," Justin wrote, in part. "Anyone who believes this is mean spirited or 10 years old or younger because a logical person doesn't talk or think this way u should be ashamed of yourself really."
Fox News’ Kathleen Joyce and Tyler McCarthy contributed to this report.