hotch asked spencer, elle, jj, morgan, and you, to go to a place where he was sure the unsub was hiding out. the thing is, this unsub had an unusual obsession problem, he would become obsessed with almost any women he met that had brown hair and blue eyes, he'd follow them, and then kidnap and r/pe them, we had found out that this was because his deceased girlfriend had similar traits. you have brown hair and blue eyes. considering spencer is your boyfriend he refused to let you go, he was protecting you.