Conversational remorse is the feeling you get after leaving a conversation and thinking of all the things you should have said when you were in the conversation, be it witty feedback, wise advice or informative message. 

Conversational remorse指跟别人说完话，你才想起来之前应该说的都没有说，这些谈话过后才想起来说的可能是机智的回击，英明的建议或者有用的信息。

因此，我们可以把conversational remorse称为“聊天懊悔”或者“聊天马后炮”。

For example:

I should have said NO to all her requests, but that was too late, there is only conversational remorse left in me.

我应该拒绝她的所有要求，可惜一切都太晚了，我只能在这里马后炮。