maybe he added that so you didnt feel like you had to match up to that?

I would drop hints at first and test his reaction. If it's positive, come out and ask some time! Good luck!

Sometimes people stick their foot in their mouths and say something they don't REALLY mean. I've done that before regarding swinging. Bring it up again and then when it comes back to that ex, mention that fantasy of yours in a roundabout way and see if he'd be game to try it with you (after all, you're not her so maybe it'll be different with you). If not, at least you slipped it in there. And you never know, the idea might grow on him after a while.

Get him to tell you WHY he hated those things with ex. Maybe he just said that because you have been more tame and he didn't want to freak you out? Tell him you would like to be more adventurous and just because something was bad with one person doesn't mean it will be with you. But you're probably going to have to be super specific with what you want if you want satisfaction. I know that completely feels like it defeats the whole tying-up thing, but trust me--if he knows what and how you want, once it's happening you won't be thinking about how you had to instruct him, just how awesome it is.