The only time i have seen someone flat out deny something so obvious , is with my narcissist ex. He would lie about stuff that i SAW him doing ! I questioned my sanity, until i got video proof of what he was denying , and he kept denying it. It was infuriating , and i dont blame you for feeling so frustrated ! Thats crazy. WHY would a person try to make you question your sanity?? Its actually mentally hurtful . WTF !!!! He even told me "does anybody in your family have schizophrenia?" knowing damn well he was lying. I think its extremely abusive.

idk ,, thats a big red flag, WHAT ELSE WILL SHE LIE ABOUT WITH NO REMORSE??? I wouldnt want to stay in a relationship with somebody who is capable of that. I suggest getting out of that relationship before it goes any further.