It sounds like you really don't trust him.
Look at it from this viewpoint.................
Maybe the woman asked him to escort her because she knows him better than the other co-workers (male) and knows she would be safer with him (instead of 3 drunk females) because he is an honest person and would not take advantage of her.
Communication is key in a relationship. He did not have to tell you anything but he did because he trusts you.
My husband travels a LOT and there are times he is completely exhausted from leaving home at 4 to catch a 6am flight, then driving 2-3 hours to make the appointments needed and not getting to his hotel until 9pm. We are in contact throughout the day and I know sometimes when he gets to that hotel he does pass out from exhaustion.
You've always trusted your hubby and you say your are best friends. Don't allow the old baggage from your father make something out of nothing here and destroy or damage what you have.
Best wishes.