Let him know how you feel, then let him think about it while you hunt elsewhere. Let him know it just isn't worth the trouble he might get in, or the friendship he may lose. Sometimes that's enough.
We have a husband and wife DNR team here in my county. The woman was our DNR rep for the safety course. I spoke with her at length about baiting. They've made many a case over illegal baiting. There's been much said about what is baiting and what isn't. In Illinois, it is considered baiting if it's edible. She said "I'm here to enforce the laws, and the laws are here to protect the game and hunting for everyone. I hunt too, and I don't want it ruined for me either."