Am I Wrong?? I ask my 7 YO Son to do something..my wife interferes.?

My wife works and goes to school so I'm the primary caregiver at this point in our lives. When I ask my 7 year old son to do or not do something my wife feels the need to undermine what I say to him and tells him to do the opposite. I'm doing my best to be consistent with him and teach him properly and I feel that what shes doing sabotages this...Am I Wrong??