What, the really slow and simple boring one? I learned it in a random 5-minute session early on in beginners classes. If you mean the complicated one, we learned that at the intermediate class with (I think) Karen - SunKitten
"The really slow and simple boring one" is social foxtrot, not slow foxtrot. PeterTaylor was deliberately rather specific when he named these pages. And thankyou. --SF
PeterTaylor observes first that Mambo is Club rather than Ballroom in the IDTA classification. Now that that's out of the way... he learnt a bit of fox in the second term of Bronze - so his 5th term of dancing. (And /VienneseWaltz? in the third term of Bronze, so don't expect your experience to be the same as mine).
M-A learnt it in Beyond Beginners. First or second term thereof.
Beyond Beginners, first term, week 3. And moderately amused at the general coincidence. --SF