1) You should attempt to re-express your loved ones position so clearly, vividly, and fairly that your loved one says, “Thanks, I wish I’d thought of putting it that way.”
2) You should list any points of agreement (especially if they are not matters of general or widespread agreement).
3) You should mention anything you have learned from your loved one and/or group..
4) Only then are you permitted to say so much as a word of rebuttal or criticism.