How do I talk dirty?

Communication in bed is not a bad thing. I think guys like it when women tell them if he is doing something right or if there is something she would like him to do. Guys like to have their ego stroked and they like to know what the woman is thinking. If the woman is talking to him about what he is doing, chances are she isn't imagining being in bed with someone else. Also talking dirty helps focus on what is happening instead of the dishes or laundry that need to get done.
Like what Vanessa and anon said, talk about what feels good. Even just start with "Mmmmm, that feels so good" and then let him take over. You can take cues from what he says next.
Or if you want him to stop wanting to talk dirty, you could say some vulgar things to really shock him. LOL

wow i could give you all kinds of tips, just would feel extremely uncomfortable telling you. just think about what turns YOU on and say them out loud. yep start from there, then later ask what he likes

Google is your best help on this:  http://www.dirtytalktips.com/

Talk about what feels good, what you want him to do to you, and how you are excited anticiapting the next step like "I can't wait until you are deep inside me"....anything along those lines. It isn't dirty, it is making love.

I am with m-avi, if he wants dirty he needs to go get a ho!

Try talking dirty while he's doing something,like you feel so good inside me,or you're making me so hot and wet

we don't dirty talk much but we do flirt over the phone or via text at work and it usually consists of what I want to do to him or what he wants to do to me... some guys like hearing a woman say vulgar dirty things (on rare occasion when we're being silly we do) such as " do you wanna lick my p... " you get the point... My DH and I have a very healthy sex life. 3 times a week at least, sometimes we just have to change up the pace to keep it interesting... hope that helps a little...

Ewww, tell him you haven't showered in a week? I don't know, I have no need for that stuff... Ugh...