What is the best approach to exposing your children to alcohol?

My almost 3 year old son wants to taste everything. He sees me drinking a beer or wine, and of course assumes it must be yummy (which it is). He insists on having some (or at minimum tasting it). Is it reasonable to let him taste a little bit of beer or wine? What if he likes it? Will the early exposure make it seem less taboo, and thus less of a draw when he is older? Or, is it better to make a stand and say, absolutely not, this is for adults only?

Edit: I’m not talking about pouring him a glass here, I’m talking about a little sip, just to taste it.