It’s OK to not be totally okay all of the time.
This doesn’t mean you should be intentionally treating him suggest, either. Both being extremely good and extremely mean are game-playing.
Neither of those will allow you to build those all-important relationship fundamentals that you need to be building at this time.
The top issue with being nice is you think he wants you to be that it means you’re constantly trying to live up to an image of the person.
Whether or not that’s whom you actually are. And that’s completely counter-productive, as it means you’re building those fundamentals on shaky ground. Stop being good, give attention to being genuine.