I have a moral question, and I really want answers.

Okay, here is the situation. I am asleep in the daytime (as usual) and my doorbell rings. It is, say, noonish. It is a sunday. At my door is a twentysomething woman and her son, who is about 8. They are well dressed, and holding copies of some colorful christian religious propaganda. I am grumpy and annoyed. If the woman had been alone, I would have either slammed the door, or given her one of a number of verbally abusive but clever lines that I keep in the back of my head for such intrusions, but the kid's presence alters the tableau a bit.

What I want to do is ignore the woman completely, kneel down, and say to the child, in a very pleasant voice "Hi. The only difference between Jesus Christ and the Easter Bunny is that your mommy thinks one of them is real." and then stand up, and smile, and hold out my hand for the mother to shake.

Am I justified in doing that?