...I have to agree with LAW...Practice does make perfect! Try exploring the anal region while you are concentrating on her clit...most women that I've been with (although not all) really enjoy a well-moistened finger gently tantalizing & then penetrating their arse. Also, a G-spot vibrator (the one with the curved tip) tends to work wonders while you are focusing on the clit.

__________________
I wish all the ladies were pies on the shelf...and I was the baker because I'd eat them all myself.
I wish all the ladies were potholes in the road...and I was a dumptruck because I'd fill them with my load.