Am I a bad mom?

I have a 12 year old daughter who ive been raising on my own. I have been in a relationship with my boyfriend for 4 years. My daughter since turning 11 and starting JHS has had an attitude. Yes, it irks my nerves but I know I am not the only mom dealing with attitudes from their daughters. My boyfriend constantly says comments like “ shes going to beat you up when she’s older” or “ shes going to kill you one day”. I grew up getting beatings and i didnt want that for my child. I handle situations accordingly and provide punishments accordingly without beating her. Ive been shrugging it off but today he said it again and im upset. Should I be upset or am I really a bad parent?