It's a risk both ways.
As a couple I have encountered many guys who claim to be bi hoping they can avoid the subject in the bedroom. So I agree, guys playing first is a good method.
On the flip side, I have more than once gone to meet a bi couple, that there really was no female. I know a number of gay guys who have used that same tactic for years. They claim to have to meet 1 on 1 first and then the next meet she will be involved. Or at the last minute "she had to run out" but he can still play.
Playing as a single. I'll meet either sexes or a couple. I just want to know up front and not be deceived.
When it's a couple. I have no problem with one on one play first with him, but only if she is there too.