How can I tell if a nice guy has a naughty side?

So there's this guy I'm talking to (who likes me) and he's suuuuper nice/sweet. Almost too nice, but I do like him regardless. Anyway, out of all this time that we've been talking, he has never once flirted with me in a sexual way of any kind what so ever. Only in sweet ways, but nothing kinky. And that's good because he's respectful, but I'm curious on how he is "action" wise lol. I'm not thinking about having sex with him, but I do wanna get a little "frisky" eventually. (Heavy making out, griding, maybe a little foreplay in time.) Anyway like I said he's been pretty shy up until recently and he's really sweet and nice and just wanna see if he's got a lil "freaky" side lol and how it is. I know he isn't a virgin because he's told me he's had sex with past girlfriends. But he has not even hinted anything sexual towards me, only been sweet. I want to sexually hint at him so I can see where he stands on his freaky side lol, but I don't want to make him feel awkward because I have no idea how he is in that way. So how can I tell? thankyou.