I'm interested in hearing your suggestions.  If your mistress says "mmm, I miss you! You know I trust you and if there is anything you have always wanted to do, fantasized about, even if you think it might be off the path per se, I would likely enjoy exploring with you."  What would want to try?  We've covered the full array of conventional lovin'

I think it would have to do with interesting textures and perhaps aromas.

It needs more thought.

It's not what I would want to try but I think she's fishing for something.  If you've tried everything else?? bondage??
I'd turn the question to her.  What is she interested in.
skb

That, or I would get nervous that things are getting too comfy...

I had a mistress when I was younger.  We were both into BDSM and wanted to cross off all the to-do or at least try list of that genre of psycho-sexual behavior.  We were true experience junkies, and your interests may vary.  Ask your mistress if she would like to experiment with coprophilia and urolagnia as the recipient of each.  I am left with nothing left to try, but at least I won't die with regrets of never having done so.

Use you imagination and have fun. There's an open invitation, what fantasies do you have?

Role play? Mind games? Scenarios? Places? Acts? Give into pure spontaneity even!

Let her body and mind be your canvas (if she is willing).

Maybe you guys should have sex in public places.

Turn the question around, and ask her what she might have in mind. She may come up with some things you didn't even know interested you.

With more trust, there are m ore opportunities to make the relationship more intense.

Whether that's exploring the pain/pleasure thing, emotional closeness, fantasies, 'dangerous' places to have sex, substances that enhance the experience, etc.

If she asked me, I have some ideas but I like a give and take, not just a take, so I'd want to hear her ideas as well.

Well, that opens up a whole new avenue of fun when I hear those magical words! Hershey Highway, here I come!

Thanks for the suggestion doneitall, but that's nasty, not good nasty either.

How about public sex in or near famous places....
tried it in Europe in Florence under the replica of the statue David, Rome at the ruins , Paris in the bushes under the Eiffel Tower, hj  on a gondola in Venice,canal street in Amsterdam......
better than the sky high club got any ideas at your city