ANSWER:

This is not kufr. You are not allowed to speak without knowledge like this as this is one of the most heinous sins in Islam according to 7:33

If you are a male, you must break all communication with her as it is not permissible to be “friends” with the opposite gender.

QUESTION: I have a friend who casually keeps singing English songs, all in their accent and all..I try 2 tell her tht dis is imitating the disbeliever, so kufr. She says its allowed to sing without instruments. How should I advise her? This is kufr right?