If I understood your question, you’re concerned about what to talk about when both setting up something like this, as well as how to discuss it afterward. There are so many variations in the games played that no one answer would be right for every circumstance. For us, what we settled on is that we were in this to have fun together. As somebody mentioned earlier in this thread, too many rules tend to get in the way of having fun.
That said something took place in this threesome of yours that upset you. You kind of beat around the bush about it but it sounded to me like the fact that the other man took the assertive role in this upset you. If he did, that’s neither right nor wrong, it’s something you and your wife allowed him to do.
What you have to remember in this is that you’re both adults and in charge of what takes place. Neither of you should worry about signals, if something is going on either of you don’t like, put an end to it. You two are the host and hostess, tell him he’s worn out his welcome and it’s time to go. Your primary role in bringing another man to your bed is to keep your wife safe, let her enjoy what she wants to, but don’t let this go in a direction she, or you don’t want to take it.
Now with that being said, there was an undertone to your post, which indicated you were upset with what took place, but she enjoyed what happened. If so, there is something else you need to keep in mind about this. In all cases in the lifestyle, whatever the woman desires is usually the right way to go. If you want to have fun in a threesome, you need to allow your wife to enjoy herself. And if you need to ask if she enjoyed herself either you, him, or both of you didn’t do your job right.
As a side note, the hardest aspect of this for most men is to release their wives to enjoy themselves and not be intimidated by another man rocking their world. Don’t look at it as a competition for whose the best, look at it as a learning experience. Personally, we’ve never played with another man who rocked my wife's world in which I didn’t learn something from the experience. When you discover some trick which will blow her mind, add it to your lovemaking repertoire to allow her to experience this with you. The best of anything will get boring in time, keep it fresh with new things and you’ll both have more fun.
As far as the communication between the two of you, there are several levels of communication, and by far the most honest is the non-verbal side. If your wife gets in the car for the ride home and she has that smile, she’s all cuddly, and has that far away look in her eye, she loved what took place. On the other hand, if she gets in the car, slams the door and screams, “Take Me Home, NOW!” She probably wasn’t thrilled with it.
You're going to want to know what she thought about what took place, and she’s not going to want to tell you if it was great, so don’t ask. If she liked it, and she can trust you, she might at some point tell you what she liked most about what happened. Put yourself in her position, if you just had the best sex of your life with another woman you’re not going to tell her that. Let her actions tell you what you want to know. Remember, women are all subliminal communicators, and if men are going to understand them, we have to learn to communicate on that level.
Oh one more thing before I end this rant, you were more than a little vague about what it was specifically that upset you. If you have something in particular which upset you, or you didn’t like in your playtime, articulate that concern. I’m sure whatever it was has been experienced at one time or another by somebody on this site.