Very well said, QS.

"...It’s not about having facts, it is about your sense of the issue.. You as a wife definitely have sense of what exactly is going on… if there is something fishy or not.. If you do feel that there is something, trust me, THERE IS!..If it is only friendship, she would respond properly, demonstrating you that there is nothing between her and you hub.."

A further note, this comes from the wife having no self esteem issues of her own. She can then observe the situation (face to face) and assess it for what it really is - whether just best friends or more than that. People can lie but their actions will speak louder than words - eventually. Notice inconsistencies, etc.

***************************************
Troubleshooter = shoots trouble in the a***