Question about tile spacing

Hi y’all!

My contractor is starting to install our kitchen backsplash. He wanted to butt the tiles against each other to minimize grout lines but I hesitated and asked if he would space them by 1/16”. He seemed kind of annoyed about that. I guess I’m just wondering if his way would’ve been correct, or if some spacing is needed for expansion/contraction? He said that was not necessary. Thoughts?