I'm Pretty Bad With Thinking of Dialoge

So what I've planned to do is use snippets from random conversations I overhear (by accident of course, I don't purposely stalk people and record their conversations).

Yesterday I was on the bus and these two people were talking about films, and it went something like this:

Girl: So do you like horror films?
Boy: Umm.. I don't know? What do you classify as horror?
Girl: Well what do YOU think horror is?
Boy: Rip slash tear?
Girl: Like Chucky or Saw or.. what?
Boy: I'm not sure, because there's horror, then there's thriller.
Girl: Well then, how do you know there's a difference?
Boy: People dying. That's horrific and that's horror.

Hahah! I want to use that somewhere in my film, with modifications of course.

xx.