Cantaloupe, referring to a male, who is jumping, is a very attractive male. Stating that there is a jumping cantaloupe in the distance, says that there is an extremely attractive man without pointing them out completely thus making this certain person feel uncomfortable. Meant to be said discreetly, this method of pointing out some attractive helps your friends look at the good looking person you encountered without the embarrassment of actually pointing them out.
Scale: strolling cantaloupe: kinda cute ripe cantaloupe: gay jumping cantaloupe: hey uhhh you are super hot
friend 1: (whispers) hey look a jumping cantaloupe!
friend 2: WHERE!? actually, he looks a little ripe to me
friend 1: but at least he is strolling right?
friend 2: eeehh sure