If she had second thoughts on your third meet, well, that sucks, but I can respect that, but to ask you to leave so they could play with your husband alone is disrespectful to you. I believe your husband was right to have a confrontational response to this. Treat Mr.101 with such a lack of respect, and you can bet your ass I'm going to be pissed.
There are plenty of single men out there if that is what they were interested in. If they aren't interested in us as a cpl, then don't waste my precious babysitter time. To find out the 4 of us just don't click is one thing. I don't consider that a waste of my time. But if they had something other than a cpl in mind, they should have been up front about it during initial conversations. If it's a case where she is having second thoughts about the Bi thing.... that's fine, nothing to be ashamed or embarrassed about, just speak up, say what you feel and most people will respect you for that.