> Oh, could I? Well, your entire face is bad." > If they respond with another insult

I seriously doubt they will. “Your entire face is bad” sounds like lashing out from a place of hurt. Typical response would probably be a confused or disgusted look followed by a change of topic.

There are not a lot of people who could pull this kind of response off without coming off extremely weird or like assholes. And none of the people who could pull this off successfully are asking for comeback advice on Hacker News.