Delete parts of a conversation

I accidently mixed up my "sparring partner projects" and asked him a questions which wasnt at all related to all the ones above. Navar answered, but I want to delete this last Question and answer, because its in the wrong project. Also, if I wanted to show a (later "share") with a colleague of mine, what I did, I might want to delete a few, which were weird to ask? Just a simple little trash icon, asking whether I really want to delete and then, gone :)