nobody asked but
self-aware
the one-line answer
An opener acknowledging your opinion is unsolicited.
Nobody asked but is the self-aware version. You know nobody asked. You are going to share anyway. The acknowledgment is your attempt at humor.
mainstream
Your coworker might use this word.
01 / in the wild
hear it move.
humor
nobody asked but this is the best way to make coffee.
I know this was not requested but I am sharing my opinion regardless.