My boyfriend friends

My boyfriend friends hate me for some reason. I really don’t understand why considering I’ve done nothing but help better there friend today they were talking about me and told my boyfriend that I’m basically bad for him and just like his ex ( she was phyco , on drugs & etc) I never did drugs until I met him an by drugs I mean cannabis. I just don’t understand ,

Should I approach them and ask them what there problem with me is or should I just let them do whatever