All I Want is to Fly with you

This is a world where being a mutant isn't illegal, but it's not good either. You have to always have your mutant visible if it's a physical mutation and if it isn't then you're branded with an 'm' on the side of your neck.
Normally this wouldn't really bother the circus, however there's one problem. Phineas and Philip are both mutants. And maybe a tiny bit in love with each other.