Is my wife liying to me about her reason for not wanting to do oral sex?

[Lando]

me and my wife have been married and have a troubled marriage lots of arguing very little sex and were currently going through couples counseling. when we have sex it is mostly mechanical and says certain positions are to painful. She says that the reason that she does not want to do oral sex any more because since she has been working as a medical assistant she has become a germaphob and finds it gross now. If it is a lie why not be blunt and tell me you know what I don't want do it because I don't like it , but even still it is wrong to all of the sudden after 3 years of marriage just stop that means that she perpetuated a lie throughout are marriage. Because it makes me think she enjoys something when she does not. I know I am no saint and I am working on being a better husband and have had more then my share of lies and mistakes that I am trying to repair