>>101648563"Oh, she told me she was a friend of yours. I was gonna ask her what to get you for our 2 month anniversary."
When dealing with a Yandere it's best to avert blame towards the other party. Your girl already thinks of all other women as lying whores trying to steal you from her. She will be more likely to believe you were a victim of an attempted seduction, than the truth. This of course puts the other girl in extreme danger, but it's worth not getting tied to a bed post for the rest of your short life. 
