Guys: how would you react to this situation?

So there's this guy that I really like, and we're in a kinda sorta relationship...very casual nothing serious but not friends with benefits. We kiss and make out occasionally, have fun and easy conversations, tease each other but we're both super busy with school and sports and we don't want to get too caught up. So I was just wondering...how do you think he would react if I gave him a quick kiss on the lips? I'm really kinda shy so it would be newish to me...and I don't know if he'll think of it as going to fast/far in the relationship. So what do you think?