Friends with benefits

So I've been hooking up with this guy for a good 3 years. Nothing serious just friends with benefits and he's not the relationship kind of guy. We recently discovered that were both exclusive to eachother. I want to try new things in bed with him but I'm not sure how to bring it up without it being awkward I don't want to make him feel like I'm trying to tie him down or anything. I don't sleep with anyone else but him and I want to try new things. How do I bring this up to him?!?