KSI has left the Sidemen after almost 13 years. On Sunday, the British content creator, real name Olajide Olatunji, announced his exit in a YouTube video, describing it as the “hardest video I’ve ever had to make in my life.” “I’ve gone back and forth on this decision for a very long time. I’ve spent months trying to figure out what the right thing to do is, but after a lot of thought, I’ve decided that I will no longer be doing Sidemen videos,” he added. He shared that that day would be his last as part of the extremely popular seven-person collective, which he called his “second family.” “We’ve traveled the world together,” he continued. “We built something that none of us ever thought was possible, especially back then when we were making random videos together playing GTA .…