Question about infidelity

Having a discussion with someone this weekend, we wondered that if cheating on your partner with someone or just ignoring your partner was an equivalent. In both instances you are denying your partner their exsistance in your relationship with that, additionally you are intenaionally freezing them out of the relationship so to speak. So is cheating something more than the conventional idea of cheating on your spouse with another person? I do believe so.
In a relationship, you have a partnership until it is dissolved through mutual agreement, or death. Now, what if, one side of that partnership fails to let the other person know they have different ideas? The unspoken or even spoken agreement between you and your partner is broken. I firmly believe this can be done through ignoring, freezing out, or becoming involved with an addiction. In taking on any of those actions it can really be said that you are no longer engaging with your partner as you should.