If you've ever been bullied you know it can have a lasting effect on your life.

One man took to Reddit explaining he was confused when his twin sister started dating his childhood bully two years ago, with the two recently becoming engaged.

The user detailed he was "bullied relentlessly" in school by a man he called Terry, which even forced him to miss school so he could avoid taking "verbal abuse."

The 28-year-old noted he was "hurt" when his sister began dating his bully and "tolerated" being around him for his twin's sake, but now he refuses to attend their upcoming wedding.

"I'll keep this as short as I can. My twin sister recently got engaged to a guy who I'll call Terry," he wrote via Reddit. "In secondary school, Terry was a year above us and he and his friends bullied me relentlessly. I'll spare you the finer details, but I'm talking 'caused me lifelong psychological issues' type of s--t. It was never physical, but it was a literal daily onslaught of psychological and verbal abuse, to the point where I bunked off probably half of Years 9 and 10 just so I could avoid it."

Due to the endless bullying, the man carries a disdain for Terry. "I'm not a hateful or spiteful person, but I absolutely despise Terry for how he treated me when we were kids," he continued. "I was hurt when my sister started dating him two years ago, but I tolerate being around him when I absolutely have to for the sake of keeping the peace."

Despite tolerating Terry he cannot bring himself to attend their nuptials. "I will not be attending their wedding or having anything at all to do with it," he said. "Why would I want to go to an event which is effectively celebrating the guy who absolutely lavished in tormenting me for almost six years of my life?"

His sister accused him of being "selfish and petty" for not attending the ceremony and for not accepting that Terry has apparently changed, despite him never apologizing for being a bully in the past.

"My sister is not happy about this. She says I'm being a selfish and petty a--hole who won't accept that people can change, although Terry has shown no indication of remorse for his behavior and has even tried to bring some things he did up like they were fun little jokes I was in on," he wrote, adding: "Our dad is on my sister's side and has been giving me a really hard time about it, though our grandparents are a little more sympathetic to me."

Many Reddit users supported the man's decision to not attend the ceremony.

"I'd make it not only clear it wasn't a joke, but it also had consequences. Also, you won't object to their wedding, but will in no way interact with him. It's your right to do so," one person wrote.

Another suggested that Terry most likely hasn't changed due to the fact he hasn't apologized. "My bf used to bully someone, and he actually did change, as shown by the fact that he went out of his way to find and apologize to this person as an adult," they wrote. "He still feels bad about it, and talks to me about it sometimes. This guy hasn’t even bothered to muster up a basic apology? He hasn’t changed at all."

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