Wondering if this is still valid:
Please note that travellers who wish to visit Mexico (regardless of their nationality or itinerary), holding a valid, multiple entry visa for the United States of America, Canada, Japan, the United Kingdom or the Schengen Space countries DO NOT need to apply for a tourist, business or transit Mexican visa.
A friend of ours wants to come to Cancun with us in Dec and he has to bring his FIL who is staying with him. FIL hold an Indian passport with a multiple entry visa to the USA. I assume that FIL doesn’t need a visa to enter Mexico and should have no issues entering the USA upon return.