CeMar: I agree with you that calling a SSM a MLC is an easy (blameless) way out for the LD spouse. And I agree that a true MLC contains lots of other behaviors such as buying that sports car you always wanted, going to bars where the patrons are generally much younger than you, and other typical MLC weirdness.
I don't know that much about your sitch, but unless you're doing these other weird things, you're probably not in a MLC. You W may see the 'dance lessons' suggestion as leaning toward MLC, but what I remember was that you had suggested it as a way for the two of you to get together and participate in an activity. Did you ever propose this to your W?