Cheating⁉️

So my bf has a friend and certain people didn’t know I was in a relationship

I thought he told her and she was saying she in a relationship with her

And he told her right in front of her we are together but she kept on saying she been with him for years

I’m so confused he said he was never in relationship with her Never did nothing with her but I really don’t know

I’m still mad but so I haven’t replied but I don’t know what I should do

I don’t believe both of them but I do want answer and want this to be dead and I’m good for burning bridges in a healthy way of course it will hurt but I rather be happy any advice and