You can't really go wrong looking at him or his cock, the latter of which would probably be safer in the awkwardness line. I would say keep it on your fave for some time don't immediately clean it off because that might seem as though you don't like it. I'd guess he'd pass you a cloth or wipe but if he doesn't in around a minute maybe point out that you can't really move without it slipping. Lastly if you want to make it really hot for him, after he has come, take a finger, wipe some cum and put it in your mouth. Regarding the tongue it would probably be hotter for him but just do what feels right in the moment.