awww that's kinda wholesome. I'm not really sure about this but maybe you can try talking it out with him, choosing your words so that it comes off as constructive criticism and not rejection. Really hope that you two can communicate better and lay out your opinions about each other more! I mean, he's making the game WITH you! Teammates give constructive criticisms to each other so that they can come to a mutual agreement and do great things together!
Hopefully that didn't sound rude xD