My boyfriend wants to be more dirty in bed

I've had guys and girls both want me to be more dirty and that's just not me.  So... I have to do some acting.  If she wants me to pull her hair, oh I'm going to pull her hair lol.. I don't get any enjoyment out of it but it gives me pleasure in giving her pleasure.  You just have to find a happy medium.  It takes time to become comfortable with it.

don't act when u n ur bf r having sex it would jus make th whole process suck. jus relax when u r having sex jus let him do his job like lickin ur vagina jus let do it dun resist it enjoy it enjoy th feeling of him licking ur vagina, enjoy th feeling u get when he fingers u, enjoy th feeling u get when he put his penis inside u n u sure will be more dirty then he expected if u rlly cant jus say it im sure ur bf will understand me n my gf had sex i told her to relax n she enjoyed th process nt only dat she SQUIRTED FIRST TIME EVER !!

What is your definition of a "dirty girl"?
There is nothing dirty about enjoying sex with your bf/gf.
If you have that attitude because of religious teaching, remember the Bible was written by men and reflects their views from thousands of years ago. If anyone can produce a scrap of parchment with God's own handwriting on it, THAT would be a miracle.
Do you really believe that God gave you/us bodies that are capable of providing so much pleasure just so He could say "Don't do it"? That's your mother's job. That would not be the loving God that I believe in. You have a part (your clitoris) that has no other purpose except to provide it's owner with pleasure.
So I feel we are designed to enjoy giving each other as much pleasure as we can.