Leaving car on while getting gas?

I’m 19yr old girl and my boyfriend just got mad at me for leaving my car on while pumping gas. Is that really a big deal? I’ve always done it and never had any issues.

OK i’m seeing all the comments there is 0 need to be rude IM JUST A GIRL. i was barley raised by anyone so i simply just did not know. now i do. what is the point of being rude?