Is this something I should be discussing now before we get to that point?
Or should I just enjoy the routine stuff for a while and then let loose later?
I would say take it slow, while I know men don't take most hints well, I think this is 1 place where you can give him a few hints and he might actually get it.
Guys always say they want a freak but most don't really know what a freak is, so take it easy on him at first see how far he is willing to go before you let loose on it depends how much you like this really freaky sex.
The question is, when do I tell him I like really freaky sex?
Not your ordinary routine stuff, but pretty much more extreme stuff.
I once had a young woman tell me before anything happened..."I like to be REALLY used." Of course the way she said it I got the point. You are already thinking he's possibly too conventional for you without knowing his preferences. Just be yourself unless your "extreme" causes suffering.......you might want to discuss it first.