I was in HERO a couple of days ago and enjoyed the massage and sex there. Some tips for the friends here
1. Do be shy to tell the Mamassan, but you make your own choice because the Mamassan will always say the boys can do everything whether they are gay or straight
2. Take a shower with the boy to start the friendly relationship
3. Try to communicate with the boy although they can speak limited English while massaging
4. Don't force him to "shoot out" if you are a top, since he has other guests waiting for him to be the top.
5. Give him a fair tip.
You will enjoy your time there.