Cheating

My bf had sex with his ex girlfriend 😭. When I asked why you did that he said you always says no to me for sex so I also have my needs soo I have done with her. Later he blocked her telling me that I am guilty for what I did. But today again she called by her's mother mobile and asked him to come over again and have sex till the time I am not having sex with him. She also said him that your gf doesn't love you that's why she was not ready to have sex with you and he thinks she is right🥺