Rather I want to say that he had a flashback to when his classmate did something to him. Brought back the trauma. Their likely age gap wouldn’t make sense for sense I to be the classmate.
Thanks so much for clearing that up
If you read any omegaverse, then you're familiar with the idea that an omega with a bite that has no alpha is constantly struggling. Whether they're always in heat, suffer trauma, can't pair, it really depends on the writer. In this universe its kinda the same concept, they can find a new Dom, but a jerkface dom classmate of his that collared him when he was younger, traumatized him. He didn't provide proper aftercare to him, leaving him in that "subdrop" state and causing him to fear all Doms (like a traumatized omega would fear all alphas)
Poor baby
I don’t understand what happened at the end there, did he recognize him or some thing?