It's seems hard to believe, not saying you're lying, but just hard to believe that the story is you danced with him for several hours, then get permission to message him one on one, then you get intimate and sexual on a level that seems alarming by your spouse and then say you are trying to setup a double date. Everything leading up to that statement of double date contradicted your intention to setup a double date, it was personal and one on one. Why in the world would you approach a double date in that manner? The way you tell the story we don't know if he (your husband) has had any interaction with the guys partner or is even remotely interested. Are you trying to alienate your spouse or make him into a cuck? Or are you covering your tracks and trying to justify meeting up with this guy and as consolation include your new boyfriends wife and give her to your husband so he won't feel left out.

This screams of big time non communication and selfishness. You need to communicate more and and be honest, because what your doing is not swinging it's just hotwifing or trying to be in open relationship.