as for providers, specifically, and their ad's stated "orientation", I really don't pay attention too much to that.....a "straight" guy I met a couple or three years ago has been married to a guy now for about a year......I presume the dudes who claim "straight" are most likely to be fudging the truth, followed by those who claim" bi", then those who say "gay".......no surprise, I suppose......
as mentioned here before ad nauseum, the best strategy is to communicate your specific hopes for the meeting beforehand and see if the provider will reply honestly with his limits, if any....