This may sound like an odd question, but how does the wife feel about her job? And her husband's job? And your schedule?
I am asking because I have been in a slightly similar situation (as the wife who resents the time the other two spent together), and I came to realize that the heart of the issue was NOT the amount of time A. (my legal husband) and C. (our wonderful partner) were spending together, but that is was that I hated my job and my schedule. I was feeling stressed and over-worked and sometimes resented the many hours of free time they had together. I had my time with A. and C. and we had our times altogether, but I worked more hours than they did combined. A. works part time and C. didn't have a job at all. I was fortunate enough to change jobs and now I LOVE what I do, so things are a lot better.
All I am suggesting is that the wife's resentment could have other roots.