Take control bro. Tell em what you want. If a girl is just laying there or whatever, I make them say stuff and do stuff. Damn... You`re having sex with them already, they`re gonna say some shit to make it better if you ask.
Plus, some chicks may not want to say it thinking they`ll seem too slutty, so when you tell them to say it, they`ll oblige. They can really get into it too, especially because you asked and they know you like it.
Fuck that, I don`t waste any time. If I want it, I`ll ask for it. I like them to say "Cum in my mouth". Louder! lol