How Do I Start A Dirty Conversation With My Man?

First off, it should be easy because most men think about dirty things majority of the time...so I've herd.

Just make it simple to start off with.
Such as:
What are you wearing today?
(if you haven't seen him)
or
how was your day?

And then make it better by saying things like:
I think you look sexy wearing that color, but your flesh tone and nothing else sets me on fire.
Or,
I can make your day even better when you get in my arms.
Just make the conversation very visual for him, and go from there pretty much...
I'm sure you can come up with something awesome.