Last year we spent a long weekend in Puebla and had a really fantastic time. It's a charming old colonial city, most parts are easily accessible on foot and Uber is readily available as well when you don't feel like walking. Food is great (it's the birthplace of mole and you can try lots of different varieties if you like it) and the dollar goes far against the peso right now, so you should find it a good value.
While there we did spend an enjoyable late Saturday afternoon at Banos Las Termas. It was very clean and well-maintained, and the locals were very friendly; after less than 60 seconds in the steam room I was on my knees enjoying sucking some hot Mexican guy off, and a few minutes later he had blown his load all over my face. That's a great way to say hello! Don't be shy if you don't speak much Spanish because, well, you don't need to speak a whole lot to have fun! But even if you just speak a little, it will go a long way, and some of the guys (especially the younger ones) speak English and love to practice.