Hmmm, Xue, I think you hit on something and may not realize it.

She loves to teach you things.

Can you apply this to your physical relationship (or lack-there-of).

Perhaps she feels you are so experienced sexually that she has nothing to teach you in that regard.

Wouldn't it be a great challenge for her to think she could rock your world in a way it hasn't been rocked. You know she needs to do the pursuing, she needs to feel like she's behind the wheel...

Now, how to proceed...any ideas?

Always rooting for you big guy!
Althea