Wearing a Short Prom Gown

For my prom I wanted to get a short dress, the gown needs to be above knee. and go for the cute look. But everybody else is getting a long prom dress and my dad said if i wear a short one i won’t fit in, and i’ll look like a tart. He said i should get a plain classy black long dress, but i want a short babydoll dress a cute colour. So what do you think, should I wear the short or long? And what do guys prefer? thanks !!