I'm In My 50's And My Long Time Girlfriend Has

I'm in my 50's and my long time girlfriend has just recently be diagnosed with HPV, About 7 years ago we had a falling out and I allowed two young ladies stay at my place for a month. During this time I was not intimate with anyone even though I was accused and now years later she (My girlfriend is assigning blame for saying I contracted it during that time. What do I do to change Her mind?