My husband now and then does go to a barber as I don't get time to cut his hair and let's face it when I get home after a long day the last thing I want to do is get the clippers out as I don't want to think about hair I just want to talk about other things. In your case put your feelings to one side for a moment
1. She hasn't cheated on you she's still your wife.
2. It's only hair and it will grow.
3. Is she going to travel all the way back to a tropical country to this same stylist to get her hair cut?.
Just think of it like this she wanted to come home fresh and surprise you. Her intentions I don't think was to hurt in any way shape or form. Though her reply could of been a little more subtle and probably could of picked her words more carefully. What you have to ask yourself is what's more precious the fact she's your wife or the fact that someone else has cut off such a dead substance (hair). Look at this and think outside the box she's a human being and still is allowed to make choices even though she's married to you. Some choices you both make through married life will upset each other over the years this is called give and take. Your best to sit down over dinner tonight and tell her how much you've missed her & tell her how beautiful she looks and embrace it and go along with it and if the subject should arise why she went to another stylist explain to her you felt a little hurt and talk about each other's feelings. But I personally would run with it and praise this situation don't fight it. A human being is like an egg if you hold it too tight it'll crack