Where is the trust?

That sucks, hopefully he'll figure out that sometimes older people get confused. He might be in a bit of shock, sometimes their stories can seen pretty real. My grandmothers new favorite story is about when I was young and ran away from home and walking down the railroad tracks and found a dead body. I'm guessing Stand By Me was on television.

Even if you were cheating on the side (which I know you're not) why would you tell your grandmother?

How would your grandmother know? And why does he believe her over you? Something there seems a bit dud

Op either your grandma has high charisma or your bf is dumb.

Pretty lamé you cant Reason with him, old people are known for those kind if mix ups

Old people can get things mixed up, and if your boyfriend can't understand at least that much, let alone refuses to listen to his own gf, you deserve better.

Did she mistake that guy to perhaps be your father? Depending on your age you both could have came in together...

n

My husband's grandmother told the family that my sister-in-law came out to her one day during a visit (gramdma has dementia). The whole family staged a intervention /coming out party for her. She's not gay. So I indirectly feel your pain. :-(