Heading to PV in April, Never been to a Bathhouse before.

I have never been to a bath house before (I live in KS where they don’t exist in pretty much every state around me.

I am taking a trip to Puerta Vallarta in April and staying in the Romantic district for a week and looking forward to a good time.

Spartacus looks interesting and I will most likely go; however, having never been to a BH before, what should I expect for my first time?