I'm going to suggest a slightly different tack here. I THINK YOUR WIFE IS TESTING YOU. Considering what you've said about her complaints in the past (about you being too easily manipulated), and your own honest feelings about being too much of a "doormat," I would suggest that you COMPLETELY BACK AWAY at this point, and send her a note something like:
"Hey, I had a great time at dinner -- it was fun. I don't want to give you the wrong impression, though, as I've been happier lately than I've been in a long time, and I'm just not sure how I feel about things between us right now. I hope you understand. Gotta run, I'm late for something, but I did want to thank you for the dinner invite and let you know what a good time I had.
Midwest" (no "Love, Midwest" or anything else mushy)
I think she's waiting to see if you will simply come running at the first drop of her "nice" hat, and I don't think your being that malleable makes her feel safe . . . at all.
