In a 7th/8th grade game, I'd most likely sternly warn the coach the first time. This level of ball is where coaches come to learn, which rightly implies that they don't yet know how to behave properly. You stifle that learning when you ignore this behavior. You aid that learning when you address it. Unless his behavior is outrageous, I'd suggest you give him a chance, one chance, to mend his ways. Give him a rather stern, completely obvious stop sign. If he doesn't take the hint, whack him fast. And the second T shouldn't be too difficult to earn either.
Now in a HS game, the coach should already know better. If he behaves in this manner, he triggers an auto-whack response.
