Very taboo. What do I do?

[AKQJ10]

For what it's worth, James McManus in Positively Fifth Street mentions someone doing the same in one of the 2003 (?) WSOP tournaments. It was viewed as a serious breach of both etiquette and rules, and I got the impression the Horseshoe dealers and management took it seriously and didn't let it happen again.

It's not worth killing the atmosphere of a good game, but I would certainly point it out publicly to the dealer, then quietly mention it to the floor if the dealer failed to do his or her job (as seems to be the case).