I'm absolutely mortified... Should I write an apology?
Most Helpful Guy
No. You never bring it up again and pretend it went away.0
Most Helpful Girl
"I apologize for singing out (very) loud to Adele. Although she is my favourite singer and I love her new album, I promise to try, from now on, never to do it again."
I think that would only make it awkward.
Unless you go and offer them a copy of the album with a note attached: "I believe I already made the introductions, here is the original".1