We have somewhat the same situation although in our case the wife is the hinge and she has 2 "husbands". So far it works very well for us and we all get along fantastic. Her other "husband" has a job where he is only home weekends so that may make it a little bit better but we have all known eachother for many years and always gotten along well with him and I being friends before all this. He lives with us in a room with a private stairway into the kitchen so he gets his private space. We split time when he is home and then I get to be with her all week as I am home most nights. I would say if you have a strong marriage try it out but if not this may not be for you. My wife and I are not trying to replace anything but she feels she has enough love to be with both. Her sex drive so far seems to be able to keep up but as I said we do split time as he and I are not sexually involved at all and are a true v relationship. We enjoy evenings at home, working outside, shopping, going out all together. If I am gone as I sometimes am on a weekend night they date and spend time together either in our bed or his but she says she prefers to be in her own bed for the night. This weekend may be a little different sleeping arrangements as she is going to make up lost time last weekend so as not to have hurt feelings anywhere but I am sure it will work out. So far we have no issues but as I said a strong marriage is the key. Also good communication between the 2 of you will go a long way as to what you both want out of this and what you all expect. She will need to be at least civil to the secondary and it would be better if you all were friends as well as lovers to her. These are my thoughts anyway so keep us posted on your progress and we will look for more.