It's fun to think about yanking her like that, but I have to be honest, I'm awful at things like that. I would never be able to make it sound believable, and if I was off even the littlest bit, she would immediately call my bluff, and say "Sure! Bring whoever you like! Can't wait to meet them!" She's smart, and she knows me too well.
Something more manageable for me would be dressed a little smarter than just to go to church, wear good cologne, act as though I have somewhere else to go, as in keep looking at my watch, and then at some predetermined time say "I gotta get going, thanks for inviting me. See you tomorrow kids. Bye!" The make my exit acting like I'm in a hurry to get somewhere I very much want to be.