I would focus on the positive.
"Hey, I read about something, can we try this...?"
"Oh, it feels really good when you do *this*, could you do more of that? It's really gets me going."
"I discovered yesterday when I was thinking of you and touching myself that *this* is so great..."
"Did you know that Margaret Cho recommends spelling out the alphabet with your tongue? Upper and lower case? She prefers the lowercase "e", herself..."

(truth!)
Could also pick up some sexy /booksvideos, instructional and umm, performance as well.
It's so easy to be gentle and encouraging growth, with fabo benefits, so why not?