A: Would you mind taking me home?
B: Oh, I...
A: Don't you turn your back on me. I need your help.
B: All right.
turn one's back on
Turn one's back on someone的意思是在别人需要帮助的时候表示拒绝，不理睬，不愿意去帮助他们。也可以用作turn one's back on something，表示“不接受某事物，不理睬某事物”。
E.g. Did she really turn her back on his proposal ?
E.g. When a danger like this is imminent; the best way is to turn your back on it and run.
E.g He's always been kind to me. I can't just turn my back on him now because he's ill and poor.
E.g. You should not turn your back on your friends when they are in trouble.
mind doing ：介意做某事
E.g. I feel like my friendship with Mike is becoming one-sided. I do not mind doing favors for him . but I wish he would help me sometimes, too.
E.g. Would you mind doing a few odd jobs today? Pick up some beer, take out the trash, and send these letters at the post office.