What's wrong with people?

I was good friends with a male colleague in work (I'm female). We just had great fun and one day he started making sexual jokes to me. It wasn't just one joke but quite a few. So made me think he was trying it on with me. I never acted on things because he has a partner!!! I did call him out on it and he twisted the story, went to management and said I was making unwanted advances towards him!!! He was scared of his reputation being ruined, so he was going to ruin mine!