"How Not To Tell Your Wife"
This is the one I actually used, "Dear you don't have to worry about the other woman I am her"!
Don't tell her in a moving vehicle, particularly if she is driving.
Oh, hi. I hope you don't mind me borrowing this outfit. I like it so much, I just had to try it on.
Dear, I'm not sure I'd like you to go on a diet, we'll be different sizes then.
Don't tell her just before a weekend trip. It will kill the trip if it doesn't kill you or her.
Darling, my eyeliner's run out, can I borrow yours?
Wow, that dress is something, but it'd look better on me.
Here is a picture of me (actually used by Karen with a prospective wife with favorable reaction)
Have you seen my Chanel No.5, dear?