There’s not a single person who can act nice all the time regardless of situations and circumstances.
It is in our nature that we go wild sometimes or we get pissed off for some unknown reason.
And if you’re being too nice all the time just because you think he’s expecting you to be that way or that he will abandon you if you’re not nice, you’re making a huge mistake.
Being too nice all the time is draining and it will make him question your personality.
He will know that you’re trying hard to be liked by him and because of that, he will lose his respect for you as well as his attraction.