Really feel for you brother. It sounds like you have a huge heart and really love your wife. This is going to really hit hard to hear but this is 100% emotional cheating. This other man being a good friend to your wife is perfectly fine when it's a drink every now and again with other co-workers and responsibly giving someone who is intoxicated a ride home, or if she is really only "friends" why not double date to dinner with him and his wife? However constantly IMing, video chats, phone calls, admitting she has feelings for him, ski trips that his wife wasn't told about and hiding out in his car down the street? I obviously can't say for 100% certainty but my cash would bet against her having been faithful to you... sorry brother.. Regardless of ANYTHING that has happened in the past, none of that is ok. You don't have to be angry while doing so but this is a come to terms conversation you should have with her. Make sure your feelings are clearly and in no uncertain terms laid out on the table that she needs to decide if her marriage and family means enough for her to close the book on a friend who is threatening YOUR marriage. Make sure she knows that you will give 100% effort in being the best husband you possibly can be to her and that besides your child she is the most important person in the world to you. If that's not good enough for her, for your own mental health you need to decide if it might be time to face a sad truth. Remember, YOU are entitled to be happy in life, end of line.