When a boyfriend tried to call out his girlfriend for her “beer gut,” she dumped him — with support from thousands on Twitter.

On March 29, Shelby Johnson, 23, tweeted a text-message exchange with her now-ex-boyfriend.

Johnson’s anonymous boyfriend — who had recently quit smoking cigarettes — had invited her to be healthier with him. As a non-smoker, she asked him, “Why I would need to be healthier? . . . I’m very healthy.”

He didn’t fully agree.

“You’re getting a beer gut, babe,” he texted. “You’ve been gaining and need to lose anyway.”

Johnson was hurt — especially because she was happy with her body. “My journey of my body has been long,” she writes in a Twitter post. “In high school I was 80 — 90 [pounds] and my doctors never figured out why I couldn’t keep on weight. At 20, I started gaining. When I did, I never felt happier and more healthy. I worked hard for this body. I am 120 pounds of pure growth.”

She took a screenshot of her boyfriend’s texts — and asked her then-200 followers if they thought she was “overreacting.”

Some 11,500 commenters chimed in with their thoughts — and the message was clear: Dump him!

Johnson gained more than 10,000 new followers from her viral tweet, including plenty of supporters.

Twitter user @EricVBailey writes, “I can tell you exactly how much weight you need to lose as soon as your boyfriend steps on a scale.”

Others, such as Twitter user @rheablah, simply couldn’t see what Johnson’s boyfriend was talking about: “There is NO fat. I am using a microscope . . . Nope. None I can see. If he has such high standards then he should be God himself.”

One used it as an opportunity to spit game: “If he don’t want that, I do! Dump the zero get with a hero,” tweeted @Bjberm.

After the tweet went viral, Johnson’s publicly shamed ex hit her up to apologize.

“I just need to get over myself,” he writes in a text message. “The internet helped me realize how bloated I was.”

Johnson seems pleased with his newfound maturity, tweeting, “This tweet going viral helped him see what a jerkoff he was to me.”

Still, she has no plans to take him back.

“All you need is someone to apologize for hurting your feelings. I don’t have to tolerate it,” Johnson tells ABC News. “When you’re in your 20s, don’t settle.”

Solid advice for all ages.