I once had a girlfriend curl into a fetal position, put her thumb in her mouth, and say, "Fuck me daddy." Now, I finished, but afterwards, we had to have a little talk.
I love a dirty talker. I once had a girl in civie life while I was fucking her rough (how she liked it) said "Fuck me like you would your Mother." That's the only time I stopped in my life and said WTF?! She was crazy....
I once talked dirty for an entire hour gfe session! Sometimes I tell dirty stories to my sub clients. It adds to the experience to talk about all the naughty things they are doing!