TLC/YouTube Teenagers Bella Vaughn and Hunter Johnson are taking the next step in their relationship. The couple, who currently appear on TLC’s Unexpected, are officially engaged after Bella announced the news on TikTok earlier this week. Bella, 16, shared the update on Wednesday (May 6), posting photos of her engagement ring alongside sweet captions celebrating the milestone. In one image, she showed off her left hand and wrote, “now the best t…