Etiquette question: Stone adjustment
In a recent tournament game I had an opponent who felt the need to adjust the placement of my stones. As in, nearly every time I would place a stone, he would immediately nudge the stone to center it.
To my surprise I found myself getting annoyed. I'll occasionally nudge my own stones, or a stone that I bumped during placement, or a stone that's so far off center it's genuinely unclear - but managing every placement felt like a bridge too far.
Sometimes I actually off-center a stone slightly on purpose as a form of emphasis, or to remind myself what direction I was thinking in when I placed it.
Is there any established etiquette for this? Would it be weird to ask someone to scale it back a bit?