I'm not suggesting directly asking these questions of the other person. I'm suggesting these as topics for you to think about if you're getting the polite excus

I'm not suggesting directly asking these questions of the other person. I'm suggesting these as topics for you to think about if you're getting the polite excuse and want the actual reason. To get that you have to actually make them more comfortable; calling them out on a polite lie obviously isn't going to do that.