I admit I would truly be upset. In fact, I did go through this situation.

There must be a background story here however that goes deeper than her leaving when the utility is about to be shut off.

Does your wife go out without you regularly and how do you feel about that? Is there then a deeper problem?

My ex was always going out and away without me. It bothered me as I never went out. His attitude was he didn't want to because he was tired and had just done so. Then go out a day later. I particularly was upset by all the business trips he took. Now, yes jealousy that he was having a good time when I wasn't was a big big factor. But an even bigger factor was that I had reason for suspicion of his behaviour while away.

So I wonder what is behind your own irritation. Is it entirely that she is having fun when you can't or does this go further.