Not sure about others, but usually when I go to the Semi-legit places (more on the legit side), i usually don't discuss extras when the massage starts.
I normally strip nude and cover myself when the MPA's come in. I'm the wait and hope type, so usually you can clue in on things like accidental brushing of the boys during the massage.
By the time you flip, you should have a pretty good feel how the massage might end.