grinning character

Hi all - I am curious about your perspectives as writers and, maybe more importantly, as readers. When reading a fantasy book, there is a very high frequency of moments in which the character speaking is "grinning". I have recently learnt from Dave King's "Self-editing for fiction writers" that one should show, not tell, and that speaking while grinning is impossible. It is possible that I now notice such instances more when they are not met, just because of this lesson...
I personally don't enjoy running into this phrase, and I researched whether this reception is shared or not. As I am writing my own story, I am wondering if other people feel the same way, or seeing the repetitively "grinning character" doesn't really negatively influence your reading experience. Looking forward to collecting opinions!