After you have exhausted logic and the various facts presented to support hunting, you will find that he still will not be satisfied. Therefore your best defense becomes a good offense, demand that he explain and justify his views, not with rhetoric, but with fact. If he brings up something you cannot refute with facts, do not try to BS your way through it, but say, I will check that out and get back to you on it, then contact a wildlife biologist or check it out at the library or on the net. Use facts, not opinion. Do not allow him to be the agressor any more, demand that he back up everything he states with fact. If all else fails, you may say (in a subtle manner) that you believe (an opinion which you have the right to express) antis suffer from various personality disorders which cause them to be the way they are and that you are sorry about that but it's just the way things are. You may not be welcome in his presence anymore but stuff happens.