Nobody is being hurt by your words. They are warning signs; not injurious in themselves to anything except people's perception of you. Even this reply betrays the couple-centric mindset. Are there two of you typing on the same keyboard simultaneously? If not, why are your sentences constructed in the plural?
It's less to do with the phrasing than it is about the unconscious thought processes behind the phrasing, and trying to tidy up the cosmetic problem without addressing the cause will just hide the issue rather than fixing it. Look at why you're approaching this as a monolithic single entity rather than as two individuals and work that out first; the phrasing will follow.
My use of the plural in this case is because both of us (My wife and I) feel we wronged our friend. And together we wish to apologize to her.
I understand that my word choice has been very confusing up to this point. I am really trying to approach this correctly but I know I have a lot to learn and I want to keep my wife involved with the conversation. Everything I have read says to involve my spouse in the conversation. I seem to be giving the wrong impression about myself and what I want.