This girl shows up at my house and says me n her had to my wife while i was at work, this is not so?

today while i was at work this girl name nora comes tro my jouse and ask for me(curtis) tells my WIFE that i been havin with her she knows how my house looks on the inside and everything, how is this? i have not had wth this girl i fronted her in front nof my wife and she still persist with this lie and i enden up slapping her which i should not have done but i was so mad because really my wife was not believing me i have not cheated on my wife and i dont plan too it troubles me that my wife never believes me and the fact that someone can come and say things to her hurts she does not even try to hear my side the only way i know this girl is from when i would catch the bus to go to work and she tried to get all up in my business then but i told her then i had a wife