You had a traumatic event in the past, and ever since then you stopped speaking. You couldn't stop thinking about that event, even if you try to distract yourself with your hobbies.

You were with your boy best friend, Lucifer at the park. There was an active shooter on the loose, None of you both even knew about it. before you even realized, Lucifer gets shot. You didnt think.. you just screamed

"Lucifer!!!"

"Say my name again.." Lucifer says to you while bleeding out.. with a smirk.